Drones and failure to properly govern.
I am all for the freedom to roam the air trust me, even though i think it is trivial mundane pursuit in which I would much rather be flying a real helicopter.
Yet these growing popularity toys, there is no other way to put it pose a serious threat to not only an individual but society as a whole. The tendency for people to gather and share opinions is outstanding.
The only regulations I have heard so far is no flying near airports or above 400 feet and nothing is to be carried for fiscal gain. Of course people that use them tend to be children or idiots, so they don't listen.
There is no regulation on weight, you can literally have a 200 pound toy fall and kill you from quite a height. There is no regulation of having the wings in cages as to not make powerful and sharp wings that could terrorize an entire city being bulletproof.
The Government literally has no regulation or mannerswell have none.
I know people and people and we need to be governed through the manufacturing process before this fascination of "flying" flies out of control.
Plus research and development is still going on until someone in the government gets paid or actually thinks that its ready for commercial use.