What Can Consumer Drones Actually See?

Can it be used as a spying tool? Will you get away with flying it undetected by whomever you're spying on? Even when it's flying 130 feet above your head, you can hear the quadrocopter buzzing back and forth. In 2014, when consumer-level quadrocopters were relatively new, I flew a DJI Phantom 2 over the doomed-for-demolition New York graffiti landmark 5 Pointz. A photographer, who had snuck in for one last glimpse of the inside before the building was flattened, noticed my camera buzzing over his head.