Gonna play devil's advocate here. Not because I disagree with the viewpoints expressed here, but because I think it's healthy in a discussion to explore all sides.
What is the big deal? Why are people so worried about pictures being taken of them if they are not doing anything that you wouldn't photograph yourself?
Kids at the pool. Parents photograph their own kids and sometimes others' kids all the time.
Do you have any proof that this guy is even filming?
And if he is so what? Are his pictures of neighborhood strangers playing
marco polo in their backyard pool going to cause harm to those people?
This reminds me of the african tribes that fear a picture of them will steal their soul. Or the people on the sidewalk that get mad because some photographer may have gotten them in a shot.
Or my personal favorite, facebook or news photos where the kids face is blurred out because they are a minor. How is showing the face of the kid sitting on the motorcycle your trying to sell going to harm the kid.
What is the harm in anyone taking a picture of anyone else? What is the big fear of photography?
Again, just trying to broaden the discussion.
I personally would just hover my drone over his yard until my batteries all died. taste of his own medicine kind of thing.