man on cellphone silhouette
A man uses his mobile phone at the Imperia (Empire) Tower of the Moscow International Business Center also known as "Moskva-City", in Moscow, Russia, Aug. 5, 2015.
Reuters/Maxim Zmeyev
In a first, a Manhattan federal judge presiding over a narcotics case has decided that drug evidence obtained through cell phone surveillance technology called "Stingray" won't be admissible in court.

StingRay (also known as "Hailstorm" or "TriggerFish") is an " IMSI catcher" basically acts like a cell phone tower, and sends out signals which force cell phones to ping them back with information showing their owner's location and other identifying information.

If an agent is tracking a suspect, the pings kind of work like the game "hot or cold." The closer you get to the phone, the stronger (or hotter) the pings will become.

Judge William Pauley on Tuesday ruled that defendant Raymond Lambis' rights were violated when DEA agents used a Stingray without a warrant to locate and search his Washington Heights apartment in Manhattan during a drug-trafficking investigation.

According to court documents, the DEA sent a technician with the StingRay to the area where Lambis lived. The technician walked around, sending out signals, until the strength of responding pings led him to Lambis' apartment building. The technician entered the building and then walked up and down the hallways until he found the specific apartment where the pings were the strongest.

Later that evening, DEA agents knocked on Lambis' door and asked his father for permission to search the apartment. In Lambis' bedroom, agents recovered "narcotics, three digital scales, empty zip lock bags, and other drug paraphernalia."

Privacy advocates say the use of the Stingray technology without a warrant encroaches on or even violates people's constitutional rights. But despite concerns, the devices have become an increasingly common and popular item in law enforcement's arsenal.

Research by the American Civil Liberties Union found that at least 13 federal agencies use StingRay technology, including the NSA, Homeland Security, the FBI and the army. In New York (and in many other states), both state and local police are equipped with Stingrays. An investigation by USA Today found that the technology was used even for routine crimes, like petty theft.

The ACLU found that the NYPD had used Stingrays more than 1,000 times between 2008 and May 2015 without any written policy on obtaining a warrant.

"If carrying a cell phone means being exposed to military grade surveillance equipment, then the privacy of nearly all New Yorkers is at risk," Donna Lieberman, executive director of the ACLU's New York branch said earlier this year.

Pauley's ruling on Tuesday follows what was celebrated as a landmark decision by privacy advocates in April, when Maryland's second highest court ruled that police need a probable cause warrant to track cell phones using StingRays.

After the decision, the Baltimore office of the public defender began reviewing hundreds of cases which hinged on StingRay technology, all of which could potentially be challenged as a result of the Maryland court ruling.