And for security reasons......
As some of you know, flying drones over DC area is forbidden since Sep. 11 2001. I understand the safety reasons behind it and I have seen a few drones modified with better batteries and upgraded motors thus giving the capabilities of transporting a few pounds worth of explosives. I'm sure that many areas will follow DC as we are turning into a nanny state (many areas already are nanny state).
If you look at the following video, what makes you think that a person with the wrong intentions can not harm others? All is needed is a little money and some basic knowledge of flying rc models. Nowadays rc models comes with GPS and basically self-flying capabilities which makes the hobby more enjoyable.
FYI: I know the guy in the video is being certified (in Germany certifications are required for everything, even to make sausages) and he is doing it for the correct reasons. You can skip to the 9:00 minute mark to see it in action if you don't want to see the entire video. Cheers!!!
https://www.youtube.com/watch?v=rW98VqJ4u18
The case for not banning drone flights in the Washington area - The Washington Post
Drone Maker Disables Flights Over Washington After White House Crash