The fence is routinely climbed or otherwise circumvented. The GAO reported in 2017 that both pedestrian and vehicle barriers have been defeated by various methods, including using ramps to drive vehicles "up and over" vehicle fencing in the sector; scaling, jumping over, or breaching pedestrian fencing; burrowing or tunneling underground; and even using small aircraft. "New York Times" op-ed writer Lawrence Downes wrote in 2013: "A climber with a rope can hop it in less than half a minute. ... Smugglers with jackhammers tunnel under it. They throw drugs and rocks over it. The fence is breached not just by sunlight and shadows, but also the hooded gaze of drug-cartel lookouts, and by bullets. Border agents describe their job as an unending battle of wits, a cat-mouse game with the constant threat of violence."