The Hollywood Sign Trust says it "will be deploying additional technology to tighten up surveillance and thus deter unwanted visitors in the future." 
 
 Who hauled tarps up the Santa Monica Mountains to change an iconic sign to "Hollyweed" hours before Los Angeles woke up on Sunday? It's a mystery for now. 
 
 But the Hollywood Sign Trust, the non-profit organization that oversees maintenance for the landmark, is looking to improve its security in the wake of this rare high-profile prank. 
 
 "The Hollywood Sign surveillance system is constantly evolving but an incident like the one that occurred early Sunday morning shows us where there are opportunities to make improvements," Chris Baumgart, chairman of the Hollywood Sign Trust, said Monday in a statement to The Hollywood Reporter. 
 
 "The new year’s prank was no exception and we will be deploying additional technology to tighten up surveillance and thus deter unwanted visitors in the future," said Baumgart. "This is more than preventing pranks or trespassing at the sign. Our concern is the safety of the neighborhood and the trespassers that put themselves at risk because it is extremely unsafe to be on the sign, let alone traversing the treacherous hillside that is home to those 9 famous letters.” 
 
 On Sunday, as the industry was ringing in 2017, a prankster or vandal or activist (or all three?) managed to hang white and black tarps over the latter two "O" letters on the landmark. The individual or individuals responsible committed a trespassing violation, Los Angeles police officer Mike Lopez told THR. But there has been no arrest made or suspect publicly identified. 
 
 A peace sign was etched in white on one of the black tarps, along with the words "A tribute to..." The other tarp had a heart shape on it and some writing. It's unclear if there was a message to the sign aside from the reference to California opting to vote for marijuana legalization in the November election. 
 
 The sign was said to be restored to normal conditions mid-morning on New Year's Day, with no noticeable enduring damage. Multiple workers could be seen in photos using a ladder to remove the tarps. By Monday, from a distance, it looked as it usually does on a cloudy day. 
 
 The sign is currently watched over by a security camera system that is monitored by the Los Angeles Police Department. It was first installed in 1994 and updated several times since. 
 
 The icon has occasionally been used to promote political messaging. In 2010, the sign was covered with red and black lettering with the words "Save the Peak" in an attempt to raise awareness about development. 
 
 Famously, in 1976, the sign was turned into "Hollyweed" by a then-student named Daniel Finegood and three others for an art project for Cal-State Northridge over the course of several hours. 
 
 When his son, Matthew Finegood, saw images of the new "Hollyweed" prank he immediately thought it was a throwback to the work of his father. "He spent about $50 on giant, four sheets — two black, two white — tied them to some stones, climbed on the sign a little bit to throw the stones and the rope over that was tied to the sheets," Finegood told THR. "So there was a lot of planning." 
 
 Added Finegood, "He was adamant that it really wasn't a prank. He was doing something that didn't harm the sign. He felt it was art and he was trying to tell the world something he believed in and that people were supportive of." 
 
 Daniel Finegood, who wasn't arrested for the 1976 "Hollyweed" prank and passed away in 2007, would ultimately alter the Hollywood sign four times during his lifetime: to "Holywood" (also in 1976), "Ollywood" (in 1987) and "Oil War" (taken down before the end of a night in 1990). He also aspired to do an April Fools' Day joke to make the entire sign disappear into the backdrop of the hillside, but the plan never came to fruition, his son said. 
 
 For now, the identity of the new "Hollyweed" prankster is obscure. "I think it was great execution that it was done in that way," said the pseudonymous artist known as Plastic Jesus, when contacted by THR. "You want the message to be the focus of the work and not the artist." 
 
 Plastic Jesus, who said he had no involvement in the new prank but has made headlines for his provocative Oscar-themed art in recent years, says he recently spoke with Los Angeles-based street artists who didn't know who would have been behind the new altered sign. 
 
 Jackass star Steve-O — himself arrested in 2015 for a Hollywood crane protest that included a sign saying "Seaworld Sucks" — pointed out as much when he took a selfie in front of the "weed" prank on Sunday. He wrote: "I don't know who did this to the Hollywood Sign, but I'm quite impressed they got away with it." 
 
 After more than a day with no word about a suspect, the incident is developing into a bit of a Hollywood mystery. Asked why the new prankster hasn't yet come forward, Finegood joked: "Maybe he's still on his plane to Amsterdam or Ecuador." ||||| The Hollywood sign was changed to say Hollyweed today pic.twitter.com/NSWmbgz9aP — Tommy Chong (@tommychong) January 1, 2017 
 
 It's not what #tourists expected see when they came up to see the #hollywood sign! Crews now working on removing tarps put up by a suspect. pic.twitter.com/gR8ZnQYo96 — Leanne Suter (@abc7leanne) January 1, 2017 
 
 Alvin Kim and two fellow hikers pose in front the altered Hollywood sign on Sunday, Jan. 1, 2017. 
 
 Hollywood residents awoke Sunday morning to find the iconic Hollywood sign had been altered to read "Hollyweed" in an apparent New Year's Day prank.The sign was vandalized about 3 a.m. by a male suspect who was recorded on surveillance video, said Lt. Guy Juneau of the Los Angeles Police Department's Security Services Division.Dressed in all black, the unidentified vandal scaled Mount Lee, made his way over a fence and then climbed onto each of the landmark's "O" letters, the lieutenant said. He then draped those letters with black tarps so they each appeared as a lowercase "e."The suspect remained at large hours after the incident. If arrested, he would face a misdemeanor trespassing charge, according to the LAPD.The agency also notified the city's Department of General Services, whose officers patrol Griffith Park and the area near the sign.As bemused tourists looked on from a nearby vantage point, park rangers removed the tarps and restored the proper text's visibility by 11:15 a.m."I thought we came to see the Hollywood sign, not the 'Hollyweed' sign," said Bruce Quinn. "But hey, it's OK with me."According to the online newsletter The Cannabist, the landmark was similarly edited to read "Hollyweed" in 1976. The lettering was also changed 10 years later as part of a publicity campaign for a movie.On Sunday morning, Alvin Kim and two fellow hikers were among those who posed for photos with the revised landmark in the background, which Kim described as "pretty cool." ||||| Secret Cameras Record Baltimore’s Every Move From Above Your browser does not support the video tag. Since January, police have been testing an aerial surveillance system adapted from the surge in Iraq. And they neglected to tell the public. 
 
 The sky over the Circuit Court for Baltimore City on June 23 was the color of a dull nickel, and a broad deck of lowering clouds threatened rain. A couple dozen people with signs—“Justice 4 Freddie Gray” and “The whole damn system is guilty as hell”—lingered by the corner of the courthouse, watching the network TV crews rehearse their standups. Sheriff’s officers in bulletproof vests clustered around the building’s doors, gripping clubs with both hands. 
 
 Inside, a judge was delivering the verdict in the case of Caesar Goodson, the only Baltimore police officer facing a murder charge for the death of Freddie Gray. In April 2015, Gray’s neck was broken in the back of a police van, and prosecutors had argued that Goodson purposefully drove the vehicle recklessly, careening through the city, to toss Gray around. 
 
 Featured in Bloomberg Businessweek, Aug. 29-Sept. 4, 2016. Subscribe now. Photograph by Philip Montgomery for Bloomberg Businessweek 
 
 The verdict trickled out of the courthouse in text messages: not guilty, all counts. Ralph Pritchett Sr., who’s spent each of his 52 years in Baltimore, stood on the sidewalk among the protesters. He chewed on a toothpick and shook his head slowly. In a city with more than 700 street-level police cameras, he wondered, shouldn’t the authorities have had video of Gray’s ride? 
 
 “This whole city is under a siege of cameras,” said Pritchett, a house painter who helps run a youth center in a low-income, high-crime neighborhood called Johnston Square. “In fact, they observed Freddie Gray himself the morning of his arrest on those cameras, before they picked him up. They could have watched that van, too, but no—they missed that one. I thought the cameras were supposed to protect us. But I’m thinking they’re there to just contradict anything that might be used against the City of Baltimore. Do they use them for justice? Evidently not.” 
 
 Pritchett had no idea that as he spoke, a small Cessna airplane equipped with a sophisticated array of cameras was circling Baltimore at roughly the same altitude as the massing clouds. The plane’s wide-angle cameras captured an area of roughly 30 square miles and continuously transmitted real-time images to analysts on the ground. The footage from the plane was instantly archived and stored on massive hard drives, allowing analysts to review it weeks later if necessary. 
 
 Since the beginning of the year, the Baltimore Police Department had been using the plane to investigate all sorts of crimes, from property thefts to shootings. The Cessna sometimes flew above the city for as many as 10 hours a day, and the public had no idea it was there. 
 
 A company called Persistent Surveillance Systems, based in Dayton, Ohio, provided the service to the police, and the funding came from a private donor. No public disclosure of the program had ever been made. 
 
 Outside the courthouse, several of the protesters began marching around the building, chanting for justice. The plane continued to circle overhead, unseen. 
 
 McNutt at Persistent Surveillance’s office in Baltimore. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 A half block from the city’s central police station, in a spare office suite above a parking garage, Ross McNutt, the founder of Persistent Surveillance Systems, monitored the city’s reaction to the Goodson verdict by staring at a bank of computer monitors. “It’s pretty quiet out there,” he said. The riots that convulsed the city after Gray was killed wouldn’t be repeated. “A few protesters on the corner, and not much else. The police want us to keep flying, but the clouds are getting in the way.” 
 
 McNutt said something about not being able to control the weather, pretending to shrug it off, but he was frustrated. He wanted to please the cops. Since this discreet arrangement began in January, it had felt like a make-or-break opportunity for McNutt. His company had been trying for years to snag a long-term contract with an American metropolitan police department. Baltimore seemed like his best shot to date, one that could lead to more work. He’s told police departments that his system might help them reduce crime by as much as 20 percent in their cities, and he was hoping this Baltimore job would allow him to back up the claim. “I don’t have good statistical data yet, but that’s part of the reason we’re here,” he said. McNutt believes the technology would be most effective if used in a transparent, publicly acknowledged manner; part of the system’s effectiveness, he said, rests in its potential to deter criminal activity. 
 
 McNutt is an Air Force Academy graduate, physicist, and MIT-trained astronautical engineer who in 2004 founded the Air Force’s Center for Rapid Product Development. The Pentagon asked him if he could develop something to figure out who was planting the roadside bombs that were killing and maiming American soldiers in Iraq. In 2006 he gave the military Angel Fire, a wide-area, live-feed surveillance system that could cast an unblinking eye on an entire city. 
 
 The system was built around an assembly of four to six commercially available industrial imaging cameras, synchronized and positioned at different angles, then attached to the bottom of a plane. As the plane flew, computers stabilized the images from the cameras, stitched them together and transmitted them to the ground at a rate of one per second. This produced a searchable, constantly updating photographic map that was stored on hard drives. His elevator pitch was irresistible: “Imagine Google Earth with TiVo capability.” 
 
 Persistent Surveillance’s Cessna. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 The images weren’t perfect. Analysts on the ground could see individual cars moving through the streets, but they couldn’t tell what make or model they might be. Pedestrians were just pixelated dots; you couldn’t distinguish a man from a woman, or an Iraqi civilian from an American soldier. Individual recognition, however, wasn’t the point; any dot could be followed backward or forward in time, which opened up all sorts of investigative possibilities. 
 
 If a roadside bomb exploded while the camera was in the air, analysts could zoom in to the exact location of the explosion and rewind to the moment of detonation. Keeping their eyes on that spot, they could further rewind the footage to see a vehicle, for example, that had stopped at that location to plant the bomb. Then they could backtrack to see where the vehicle had come from, marking all of the addresses it had visited. They also could fast-forward to see where the driver went after planting the bomb—perhaps a residence, or a rebel hideout, or a stash house of explosives. More than merely identifying an enemy, the technology could identify an enemy network. 
 
 McNutt demonstrated the prototype to a group of Marines at a California base in 2006. “They called up their general,” McNutt recalls, “and when he saw it, he said, ‘I need this, and I need it right now—in Fallujah.’ ” 
 
 Eventually another military unit took control of the project and completed the development of Angel Fire at the Los Alamos National Laboratory in New Mexico. In 2007 the technology was deployed to Iraq. Angel Fire was eventually upgraded with all-weather and nighttime capabilities and then used as the basis for another system, called Blue Devil, which coupled wide-area cameras with narrow-focus zoom lenses in the same package. 
 
 McNutt retired from the military in 2007 and modified the technology for commercial development, increasing the number of cameras in the assembly to 12 and making the apparatus lighter and cheaper. He began attending security trade shows to fish for clients. His first real customer approached him at a security expo in Miami. His name was José Reyes Ferriz, and he was the mayor of Ciudad Juárez, in northern Mexico. In 2009 a war between the Sinaloa and Juárez drug cartels had turned his border town into the most deadly city on earth. 
 
 Dissecting a Murder in Juárez From Above An air-based spy system zooms in, swoops down streets, and goes back and forth in time as a drug deal in Juárez blows up below. Watch Ross McNutts’s demonstration of Persistent Surveillance’s aerial surveillance technology. 
 
 Reyes Ferriz offered enough money for a couple months’ worth of surveillance, and McNutt, who’s married with four children, left Ohio to temporarily set up shop at the border. Within the first hour of operations, his cameras witnessed two murders. “A 9-millimeter casing was all the evidence they’d had,” McNutt says. By tracking the assailants’ vehicles, McNutt’s small team of analysts helped police identify the headquarters of a cartel kill squad and pinpoint a separate cartel building where the murderers got paid for the hit. 
 
 The technology led to dozens of arrests and confessions, McNutt says, but within a few months the city ran out of money to continue paying for the service. Reyes Ferriz left office to mount an unsuccessful campaign for state governor. 
 
 For the next couple of years, Persistent Surveillance survived by providing services such as traffic-flow analysis for municipal planners, wildlife monitoring and border surveillance for federal agencies, and security monitoring for single events ranging from the Brickyard 400 Nascar race to Ohio State University football games. The company also did short-term projects in six countries, including in Central America and Africa, but the nature of that work is confidential, protected by nondisclosure agreements. The combination of those projects earned Persistent Surveillance about $3 million to $4 million a year in revenue, according to McNutt. 
 
 A single, long-term contract with an American police department would be worth about $2 million a year, he says. By 2012, McNutt was approaching the police departments of the 20 most crime-ridden jurisdictions in the country, marketing his services. He floated several of them an offer: Let us fly over your city to show you what we can do, and then you can decide if you want to hire us. 
 
 The Los Angeles County Sheriff’s Department quietly took him up on the offer, allowing him to conduct a nine-day trial run over Compton, a largely minority city south of L.A., in 2012. According to Patrick Bearse, operations lieutenant for the Aero Bureau of the sheriff’s department, the county recognized the potential of Persistent Surveillance’s service, but it didn’t sign a contract with the company because the technology, particularly the quality of the images, didn’t meet the department’s expectations. The city’s residents didn’t find out about the flights until a year later. Angry protesters demanded a new “citizen privacy protection policy” from local leaders, but even those leaders—from the mayor on down—hadn’t been told about the test program. “There is nothing worse than believing you are being observed by a third party unnecessarily,” Compton Mayor Aja Brown told the Los Angeles Times. 
 
 The next city to try McNutt’s technology was his home base of Dayton. After the L.A. County trial, he improved the system by more than doubling the resolution, to 192 megapixels, increased the archive’s storage capacity, and sped up the image processing to allow analysts to conduct multiple investigations simultaneously. The Dayton police department and the city council were sold on it, and they aired the idea for a contract at a series of public hearings. Joel Pruce, who teaches human rights studies at the University of Dayton, helped organize the opposition. To the objecting residents, it seemed as if it hadn’t occurred to city leaders that the surveillance program might be interpreted as a violation of some vital, unspoken trust. “At the hearings, nobody spoke in favor of it except for the people working for the city,” Pruce recalls. “The black community, in particular, said, ‘We’ve seen this type of thing before. This will target us, and you didn’t even come to us beforehand to see how we’d feel about it.’ ” Dayton’s city leaders dropped their attempts to hire the company after those hearings. 
 
 Last year the public radio program Radiolab featured Persistent Surveillance in a segment about the tricky balance between security and privacy. Shortly after that, McNutt got an e-mail on behalf of Texas-based philanthropists Laura and John Arnold. John is a former Enron trader whose hedge fund, Centaurus Advisors, made billions before he retired in 2012. Since then, the Arnolds have funded a variety of hot-button causes, including advocating for public pension rollbacks and charter schools. The Arnolds told McNutt that if he could find a city that would allow the company to fly for several months, they would donate the money to keep the plane in the air. McNutt had met the lieutenant in charge of Baltimore’s ground-based camera system on the trade-show circuit, and they’d become friendly. “We settled in on Baltimore because it was ready, it was willing, and it was just post-Freddie Gray,” McNutt says. The Arnolds donated the money to the Baltimore Community Foundation, a nonprofit that administers donations to a wide range of local civic causes. 
 
 In January, McNutt opened the office above the parking garage. The only sign greeting visitors is a piece of copy paper taped to the door that reads “Community Support Program.” 
 
 Almost everything about the surveillance program feels hush-hush; the city hasn’t yet acknowledged its existence, and the police department declined requests for interviews about the program. On Aug. 10 the U.S. Department of Justice released a 163-page report that detailed systemic abuses within the Baltimore Police Department, including unlawful stops and the use of excessive force, that disproportionately targeted poor and minority communities and led to “unnecessary, adversarial interactions with community members.” Within a week, civil rights groups filed a complaint with the Federal Communications Commission claiming that the department’s warrantless use of cell phone tower simulators known by the trade name StingRay—an activity the police acknowledged last year in court—violated federal law and targeted minorities. “The problem of radicalized surveillance is particularly pronounced in Baltimore,” the complaint stated. The city was already on the defensive, even as the aerial surveillance program was shielded from the public eye. 
 
 Analysts in the Baltimore office. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 Around 11 o’clock each morning, a printout is delivered to the Persistent Surveillance office listing all the crimes logged the previous day by Baltimore’s computer-aided dispatch—or CAD—system. The company has hired a former Baltimore cop to act as a liaison between the company and the police force, and he scans the list for cases Persistent Surveillance’s analysts might help solve, highlighting them with an orange marker. 
 
 On a Friday in late June, not long after the Goodson decision, six analysts sat at separate workstations inside the office suite. The analysts ranged from their early 20s to their late 50s. McNutt brought four full-timers with him from Dayton, and he’s hired several more from a local temp agency, paying $10 to $15 per hour for entry-level trainees. 
 
 Terrence Rice, a 25-year-old from Baltimore County, was one of the local hires. It was his third day on the job, and he was still getting the hang of the software. For practice, he worked on a weeks-old case involving the illegal dumping of wood. He stared at an aerial image on the twin large-screen monitors on his desk. He struggled to track a pickup as it proceeded north, squinting to differentiate between the target vehicle and others it passed on a busy roadway. He kept his cursor over the truck as it advanced frame-by-frame. “It reminds me of playing a video game,” he said, his eyes rarely leaving the screen, his back bent as he leaned in close. “And that’s what they told me over the phone. They said that if I was into video games, I might like this work.” 
 
 The highlights of the previous day’s CAD list included 13 burglaries and 11 hit-and-runs, and all of the analysts were reviewing archived images instead of tracking the live feed. They were prepared to instantly drop their individual investigations and collaborate, however, if the police called with a report of a high-profile crime, like a homicide or violent assault. 
 
 Aerial view of Baltimore from Persistent Surveillance’s Cessna. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 One afternoon in February, every analyst in the office had pitched in when the police responded to the shooting of a 90-year-old woman and her 82-year-old brother, who’d been hit while walking in front of a bus stop on Clifton Avenue in the Western District. In a city where gun violence had lost much of its power to shock, the crime struck a local nerve. TV crews descended on the scene, sensing a big story. 
 
 McNutt’s analysts called up the aerial images and began tracking vehicles leaving a busy shopping center across the street from the bus stop, where witnesses had placed the shooter. For about two hours, they mapped the routes of several cars leaving the parking lot, until a detective informed McNutt that the shooter probably had left the area on foot. Rewinding to the moment of the shooting, they quickly pinpointed a person who appeared to scramble away from the scene just after the gunshots. 
 
 He was little more than a faint, grainy dot with no identifying characteristics. After he crossed the parking lot, he walked past a Subway sandwich shop and proceeded down a hill behind the shopping center. He cut a corner to cross a vacant lot and ducked between two houses on a quiet residential street. Then he approached what seemed to be a stationary object sitting in the backyard of one of the houses. The analysts toggled their screens to pull up Google Earth’s Street View, and the image—taken months earlier—revealed that the object in the backyard was a car, abandoned on the grass. The suspect stopped briefly at the car before walking a few doors down and into a house. 
 
 While he was inside, a vehicle pulled up to the front of the house; a person exited the house, got in the car, and traveled about three miles to Bons Secours Hospital. The analysts tracked him into the emergency room entrance. 
 
 Because the analysts had lost so much time while tracking the cars leaving the parking lot, all of the movements they were watching were a few hours old. When the police went to the emergency room, the hospital wouldn’t release any patient information. With no identifying information at hand, the trail seemed cold. 
 
 It wasn’t. The police later that day determined that the house the suspect may have entered before he went to the hospital belonged to the girlfriend of Carl Anthony Cooper, a man with a long criminal record. Additionally, they discovered that when the suspect walked away from the shopping center, he’d passed in front of a ground-based security camera. Accessing that footage and reviewing Cooper’s mug shots on file, they found a possible match. The police couldn’t immediately figure out why he went to the hospital; some speculated that his gun might have accidentally gone off when he tucked it into his pants and the bullet grazed his leg. 
 
 Two days after the shooting, the Baltimore Police Department posted an archived picture of Cooper on its Facebook page, labeling him the city’s “Public Enemy #1.” It also posted the footage captured by the ground-based security camera, which showed him calmly carrying what appeared to be a bag of food in one hand and his cell phone in the other. 
 
 The footage baffled Facebook users, who couldn’t figure out how it implicated Cooper. In the comments section, one wrote that if the man on camera really was the shooter, he surely would have dropped his food and run. Another commenter typed: “Not saying this isn’t the suspect but what is being seen that we, the public, isn’t seeing???” Finally someone posted, “Can a detective chime in and let us know what additional information leads you to believe that he is the suspect?” 
 
 No one from the department responded. But Cooper was eventually apprehended by federal marshals in North Carolina and sent to Baltimore, where he remains in custody. The police held a press conference to announce Cooper’s capture, saying he’d face charges for the shootings, including attempted murder and assault. Nothing was said about the surveillance plane. 
 
 Detail from an analyst’s screen. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 Even six months after the flights began, some Baltimore police officers still didn’t know exactly how the surveillance program worked. But word was spreading. 
 
 One morning in June, three plainclothes officers showed up to see McNutt. They were members of a special unit charged with investigating dirt bike crews—groups of primarily young men who recklessly drive illegal off-road motorcycles through the city. In Baltimore the crews are infamous for aggressively disrupting traffic, ignoring stoplights, and occasionally injuring and killing bystanders. Should a car accidentally collide with group members, other riders have been known to assault the driver before speeding away. City policy prevents police from chasing the bikers, because high-speed pursuits are deemed too risky. 
 
 The officers wanted to learn more about the surveillance system, and McNutt led them to a conference room to give them a demonstration. Using two large projection screens, he delivered the sales pitch he’d honed for trade shows. He called up old images from a murder in Juárez and walked the detectives through the tracking process that had led him to a cartel safe house. The spiel lasted about 20 minutes. When it was over, the sergeant in charge of the unit sat in silence for a moment, his arms crossed on his chest. 
 
 “I’m sorry,” he said. “But oh my God—this is just overwhelming right here. This is amazing.” 
 
 One of the other officers slapped the tabletop. “Let’s go get some dirt bikes, Sarge!” 
 
 The sergeant said he expected the dirt bikes to be out in force that Sunday, and some might be entering the city from out of town on Saturday. When one of the officers asked if the plane might be flying that weekend over the west side of the city, where police suspected several of the bikes would be stored, McNutt said he would make sure of it. 
 
 That Saturday morning, the Cessna rolled out of a hangar at the Martin State Airport, about 10 miles east of downtown Baltimore. The plane was scheduled to make two flights of about five hours each, with a break to refuel. The pilot for the first flight was a man who declined to identify himself but said he was a local firefighter who’d flown for the U.S. Army. David Trexler, Persistent Surveillance’s director for operations, rode along in the back of the plane in case there were glitches with the cameras’ data link to the analysts. Trexler met McNutt when both were in the Air Force, and he’d worked on Angel Fire in Iraq. 
 
 Trexler aboard the plane. Photographer: Philip Montgomery for Bloomberg Businessweek 
 
 The plane took off, and as it rose over the buildings of East Baltimore, the cockpit was noisy. The camera array was bolted onto the floor rails where seats normally would be, and it hung out of a broad opening in the fuselage, where the wind rushed through. 
 
 The Cessna leveled out at 8,500 feet, an altitudinal sweet spot between the planes approaching for landing at BWI Airport and those flying higher en route to the Washington airports. Occasionally, the Cessna has had to share airspace with an FBI airplane. Last year, two days after the Freddie Gray riots began, the FBI flew over Baltimore for five days—actions that were discovered when local aviation enthusiasts noticed a plane’s strange flight orbits on a public website that tracks radar data. According to information and footage released this summer by the FBI, its plane wasn’t doing the sort of wide-area motion imaging that Persistent Surveillance does but instead was zooming in on specific targets. McNutt says the FBI doesn’t coordinate its flights with him, and he doesn’t know what the agency is investigating; however, when his plane is in the air at the same time as the FBI’s, air traffic controllers insist that McNutt’s plane remain at a lower altitude than the federal craft. 
 
 From 8,500 feet, some of the landmarks below were easy to pick out. Pimlico Race Course to the north. The bold diagonal line of Pennsylvania Avenue. Paddleboats dotting the Inner Harbor close to the shore and sailboats scattered farther out. The just-detectable baseball players taking the field at Camden Yards. The Orioles were playing a doubleheader against the Tampa Bay Rays that afternoon; Trexler commented that the police were concerned Black Lives Matter demonstrators might try to disrupt the games. (Those concerns proved to be unfounded.) 
 
 Trexler was able to look at the cameras’ integrated aerial image on the computer on the plane, and he could chat with the analysts on the ground via instant message. About two hours into the flight, while he and the pilot were trading war stories about their respective tours in Iraq and Afghanistan, a message popped up. “Here we go,” Trexler said. The police had called in a shooting on the west side. “They’re probably following a bad guy through the city right now,” he guessed. 
 
 The analysts were, in fact, tracking a black SUV that had left the crime scene, and they saw that it had passed in front of three different ground-based police cameras. Those images gave them a clear picture of the suspect’s vehicle. Eventually, however, the vehicle drove beyond the range of the plane’s cameras, out of the city. They lost its trail. 
 
 Minutes later, Trexler announced, “Looks like we’ve got a new priority!” An off-duty Baltimore police detective had collided with a dirt bike rider in West Baltimore. When the detective got out of her unmarked car, other riders assaulted her. The crew probably had no idea that the officer was Dawnyell Taylor, the lead homicide detective in the case of Gray. 
 
 It was exactly the sort of crime McNutt and the analysts on the ground had been primed to follow. They tracked the motorcycle involved in the accident and followed it for an hour and a half. It passed several ground-based cameras, and the police got good images of the rider and the passenger sitting behind him. Police eventually found the motorcycle, confiscated it, and arrested the man they found sitting on it. 
 
 McNutt prides himself on being a student of efficiencies. In the airport residence hotel where he’s been living since January, he keeps a closet of cargo pants and identical black polos—a uniform that saves him the trouble of choosing what to wear each day. His goatee is a recent experiment to see if he can cut grooming time by limiting the surface area he shaves (results are pending; tending to the edge work, he’s discovered, takes time). And in 2014, when he was strategizing how he might best silence the sort of criticism he’d attracted in Compton and Dayton, McNutt attempted to save time and trouble by directly approaching the ACLU, the organization he figured would be most likely to challenge his system on privacy grounds. 
 
 He visited the ACLU’s headquarters in Washington, and in the office of Jay Stanley, a senior policy analyst and privacy expert, McNutt explained why his cameras weren’t a threat. The aerial images couldn’t identify specific people, because the target resolution would be limited to one pixel per person. The analysts zoomed in on specific areas only in response to specific crimes reported to the police. To further ensure that his employees weren’t spying on random people or addresses, everything they did was logged and saved—every keystroke and every address they zoomed in to for a closer look. Vehicles would be tracked only over public roads in areas where people have no expectation of privacy. 
 
 McNutt cited a couple of U.S. Supreme Court cases to show Persistent Surveillance wasn’t in the business of wanton intrusion. In 1986 a case from California hinged on whether police had the right to fly over a man’s property to see inside a fence in his backyard and then bust him for growing marijuana. The court backed the police, saying that “any member of the public flying in this airspace who glanced down could have seen everything that these officers observed.” Three years later, the court similarly upheld the arrest of a man busted for growing marijuana in a greenhouse after police in a helicopter spotted the plants through the roof, which was missing two panels. 
 
 Every week, we interview the journalists behind Bloomberg Businessweek’s cover story. In this edition, we speak with Monte Reel, author of “Secret Cameras Record Baltimore’s Every Move From Above.” 
 
 Stanley heard McNutt out and thanked him for taking the initiative to seek the ACLU’s feedback. But McNutt’s presentation shocked him to the core. As he listened to his visitor describe the type of surveillance the company was capable of doing, Stanley felt as if he were witnessing America’s privacy-vs.-security debate move into uncharted territory. 
 
 “My reaction was ‘OK, this is it,’ ” Stanley recalls. “I said to myself, ‘This is where the rubber hits the road. The technology has finally arrived, and Big Brother, which everyone has always talked about, is finally here.’ ” 
 
 The meeting took place before McNutt’s work with Baltimore was arranged, and Stanley knew other companies were beginning to work in the same general field. For example, the creators of Constant Hawk, a system that had competed for military adoption with McNutt’s Angel Fire, started a company called Logos Technologies, which provides wide-area motion cameras to organizations that can mount them to aircraft and analyze the images. (“We sell the diamond, and someone else has to mount it in the ring,” company spokesman Erik Schechter says.) This year, Logos landed its first nonmilitary contract, partnering with a Brazilian company called Altave to provide aerial monitoring of the Olympic Games in Rio de Janeiro, via blimplike aerostats floating above the city. As the sector continues to mature, Stanley predicts that more companies will enter the marketplace, and each will try to one-up the other to please law enforcement agencies, creating more flexible—and more intrusive—camera and tracking systems. The Supreme Court decisions that McNutt cited, he says, might not apply. The previous court rulings didn’t take into consideration the constancy of these systems: It’s true that anyone might be able to see into someone’s fenced-in backyard from a passing plane, but was it reasonable to argue that anyone could follow a person’s movements across a city for hours at a time? To Stanley, these are open questions. 
 
 One afternoon in June, McNutt watched his analysts dig through archived images of traffic accidents. “I’m tired of these little hit-and-runs,” he said. “Let’s have some shootings!” If it sounded crass, it wasn’t intentional; he meant the statement as a declaration of confidence in his system’s ability to solve the worst crimes, the ones that most gravely endanger public safety. He’s convinced his system can be used to examine police behavior, too, in an objective, dispassionate, and nondiscriminatory way. 
 
 McNutt often says that when he stares into the computer monitors, the dots moving along the sidewalks and streets are mere pixels to him. Nothing more. If anyone else wants to project identifying features onto them—sex, race, whatever—that’s their doing, not his. Even as the technology advances and the camera lenses continue to get more powerful, he says, his company will choose to widen its viewing area beyond the current 30 square miles rather than sharpen the image resolution. He’s exasperated when his system is criticized not for what it does, but for its potential. Yet for critics like Stanley, the two can’t be separated. When told that Persistent Surveillance Systems had been operating over a major city for months, Stanley predicts, “I would expect fierce controversy over this.” 
 
 McNutt says he’s sure his system can withstand a public unveiling and that the more people know about what his cameras can—and can’t—do, the fewer worries they’ll have. But the police ultimately decide who and what should be tracked. In a city that’s struggled to convince residents that its police can be trusted, the arguments are now Baltimore’s to make. 
 
 (Corrects the year McNutt met with Stanley in the 54th paragraph.)
– The nonprofit that cares for the Hollywood sign says it will be "deploying additional technology to tighten up surveillance" after the sign was altered to read "Hollyweed" on Sunday. The black and white tarps that transformed the sign had been removed by mid-morning on New Year's Day with no damage to the letters, prompting police to abandon a search for a suspect. But the Hollywood Sign Trust says it will adopt new measures to "deter unwanted visitors in the future," reports the Hollywood Reporter. These could include updates to the existing security camera system, which recorded a "lone individual" dressed in black hanging tarps from the letters around 3am Sunday, reports the Los Angeles Times. Such an incident "shows us where there are opportunities to make improvements," says the trust's chairman, adding the group will work with police to discover the weak link in its security. "Our concern is the safety of the neighborhood and the trespassers that put themselves at risk because it is extremely unsafe to be on the sign," which a student also altered to read "Hollyweed" in 1976 as part of an art project. The existing security system includes 35 cameras that watch the sign and hillside. The area is also protected by a wrought-iron fence and a police officer in a guard house, which is manned at all hours. The Times notes rain and clouds may have provided concealment for Sunday's trespasser.