Have you ever spent time in a security station with decent cameras? I can only imagine what they are like now, but in the late 90s, after we put up our new headquarters, that included a NOC (and therefor a 24x7 security station), we had the bubble cameras with really, really amazing zoom. The security team, having absolutely nothing to do (this was sunnyvale on Mathilda Avenue, not really a hot bed of things to be worried about) - spent all of their time using the camera to intrude on people's privacy, in a very intimate manner. They zoomed on apartments, they zoomed on cars, they zoomed on hotel windows. They were able to count the change at the fast food restaurant across the road. And this happened all without people ever being aware.
The difference with the cameraman, is he is letting people know what he is doing - there is no deception. That's the entire point, people are under _incredible_ amounts of surveillance, without their permission. Sometimes very intimate moments are being captured.
So - while it feels extraordinarily intrusive to deal with this guy, if it gets a conversation going around what's being captured, and recorded, without your knowledge - then I think some good can come of it.