As reported in the Washington Post this week:

In recent days, drones have smuggled drugs into an Ohio prison, smashed against a Cincinnati skyscraper, impeded efforts to fight wildfires in California and nearly collided with three airliners over New York City.

Earlier this summer, a runaway two-pound drone struck a woman at a gay pride parade in Seattle, knocking her unconscious. In Albuquerque, a drone buzzed into a crowd at an outdoor festival, injuring a bystander. In Tampa, a drone reportedly stalked a woman outside a downtown bar before crashing into her car.

Because drones do not need to be registered, the potential for harm is always going to be there. For a few hundred dollars you can remotely operate a vehicle anonymously. I foresee a time when all drones need to be registered, just like cars.