Definitely this. This summer a guy was flying a drone over a popular park area where lots of people were swimming in the river; it was extremely annoying. I'm pretty sure the drone was above the legal weight limit too, and as I have a UAV license, I'm well aware that it's illegal to operate a drone directly above other people. I spotted the guy with the drone controls but decided not to talk to him about it, because I couldn't be certain that someone as inconsiderate as that wouldn't necessarily react violently.