FAA Certified drone pilot in the USA here. That's wild. In the US it's illegal to shoot down an aircraft of any sort no matter the type or who is flying it. And also, the Federal Aviation Administration is the only authority in the US when it comes to airspace, and as long as you have authorization from the FAA or are in uncontrolled space, you can fly over anyone's property. However, that doesn't give you the right to voyeurism or harassment. If you are intentionally spying on things that are normally considered private (peeking in a window, for instance) or repeatedly or specifically bugging a specific individual or family, then you can still be charged with those crimes. Also, unless you have a specific waiver that's rather hard to get, you have to be within line of sight of your drone. If the drone pilot is not following the rules, they can be hit with hefty fines. Even though drones can be bought easily, there's still strict rules that the FAA has for both recreational and professional flying, and anyone operating a drone outside those can and should be reported.