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.

The altercations are the byproduct of the latest consumer craze: cheap, easy-to-fly, remotely piloted aircraft. Even basic models can soar thousands of feet high and come equipped with powerful video cameras — capabilities that would have been hard to foresee just a few years ago.

Reports began surfacing last year of runaway drones interfering with air traffic and crashing into buildings. But the problem has grown worse as drone sales have surged.