Airports have long been protected airspace, effectively forbidden to drone operators, but that hasn't stopped rogue drones from venturing into that space from time to time. The FAA also recently clarified the laws around race tracks and sports stadiums, imposing criminal charges on anyone who flies a drone too close to an event with more than 30,000 people present. The FBI has been tasked with investigating rogue drones since at least 2013, although it's typically extremely challenging to track down the operator responsible for a given drone.

That's given rise to a profitable business in anti-drone technology, technology that's particularly attractive to airports, prisons and stadiums. The FAA recently contracted a system that would identify rogue drones that venture into controlled airspace, according to documents recently obtained by Motherboard, although the details of that system are still unclear.