Watching an uncontrolled drone strafe an overpass at street level and split power lines for a commuter train, really increases my sympathy toward those who want to regulate these.
Pigeons usually do not have fast-spinning blades attached to them. I am not really for regulation, but these things can actually hurt people [1]. RC Helicopters (with one large, main rotor) have actually killed people [2].
Hobbyists must take great care to operate their drones safely, and companies should assume some liability for runaway situations like this if they ever result in injuries.
So can people with knives or swords, or baseballs propelled by a bat. Anyway, I suspect that all of those quadcopter injuries occurred while the owner was setting up the quadcopter. Every story I've read (mostly from my frequent visits to RC hobby forums) is from people attempting to test functionality on a bench with the propellers on, or perhaps a few people who attempt to take off with their aircraft right at their feet. The RC helicopter death is a valid point, but that's the only RC aircraft related death I know of, and helis like his pretty much self-regulate because they're expensive, require mechanical knowledge to setup and maintain, and will mostly likely never get off the ground if flown by someone who doesn't know what they're doing.