There are basically three ways to stop a drone, said Jeremy Gillula, a staff technologist at the Electronic Frontier Foundation: block the radio signals linking the drone to its controller, hack the aircraft's control signals and trick it into believing it is somewhere else, or physically disable it. Some drone manufacturers program a "geo fence" — location coordinates that their drones treat as off limits, and refuse to fly past — into the drone's programming. Police also could physically knock a drone out of the air with a projectile or use a net to catch it.
"If it were me, that would actually be the first thing I would think about doing," Gillula said. "You would have to basically encase the White House in this net. It sure wouldn't look pretty, but in some ways it would be the most effective way."