Appears most of the comments are from conspiracy theorists. (usual internet trolling)
The consensus is that they are worried about peeping toms spying on their underage kids.
As a drone operator, I can say it's pretty hard to get a good shot of a person unless you are flying pretty close. (however, I haven't explored alternate lenses for my GoPro). I also refrain from hovering over personal property for too long, and especially not at a low altitude.
Without being there to witness the events, it's hard to say which party was really acting inappropriately. If the operator was hovering low and in the shooter's personal space, I can understand him being irate. Was shooting it down the right idea? Probably not. There may have been a better solution.