The law of unintended consequences has just gone into effect with the drones. Just think how easy it would be capture a military drone in flight or any drone for that matter and then use it as an assassination weapon to go after who knows who. Then they could blame it on the military or sheriff that was supposed to be in control.
Think in terms of one of the drug cartels capturing control of a drone over the ocean and diverting it so that there was an open path to run the ships through. With so many drones in the air it would be hard not imagine this happening.
Then think in terms of vigilante justice where some group or even a person wants to settle a score or right a wrong.
Researchers are finding this possibility a very high probability.