I can imagine the opportunity for crime, knock a few of them out of the sky, steal their merchandise. Even assuming they had some form of GPS tracking or alert system, it would take law enforcement time to be alerted and track down the felled drone by which time the perps will be long gone.
OK, work with me here: escort drones armed with laser designaters and air-to-surface missiles. EAT FLYING DEATH, BOOK THIEF!!