I built an ArduPilot quadcopter a while back and had some fun with it, but now basic quads are available at Fry's for a hundred bucks or so and there are going to be more stories like this.

I think requiring a basic license of some form is a good idea, along with allowing FPV flight out-of-sight as long as you have an appropriate license, but beyond that law enforcement is probably gonna end up having to get some new tools to deal with this.