At least based on this article "Know Your Rights: Photographers" (http://www.aclu.org/free-speech/know-your-rights-photographe...) what he is doing is perfectly legal: video-taping while standing on public property. On private property it is not ok and you have to leave when asked, which he does.
The situation only gets tricky because of the audio, and in this case it matters what state you're in. Still, it seems like the legality hinges on "reasonable expectation of privacy", which someone casually sitting at a Starbucks probably does not, or at least should not have. Also, in all cases the subject is clearly aware of being recorded.
On the other hand, in one of the clips two guys call the police and he runs away trying to avoid confrontation. That seems odd.
Running is a good idea because many photographers - not creepy photographers - have been arrested for taking photographs of the public, in public.
The Metropolitan Police (London, UK) had to give advice to officers and the public about the law because so many people were being harassed unfairly.
Unless your intent is to become a civil rights test case, avoiding police confrontation as a photographer is almost always the best move.
IANAL but the main difference between surveillance video and his supposed demonstration here is that he is publishing them for public viewing.
I expect that would require a release form of some kind to be signed as as such is violating some laws.
The act of videoing itself is probably not against the law, but doing it without the express permission of the subjects with the view of publishing it later, is.
Publishing is perfectly legal, though commercial use opens one up to potential suits.
This usage is very clearly editorial. This guy is on solid legal ground.
 Commercial use is a legally tested term, not a lay one. It does not mean "selling for money", but has more to do with implied endorsements. You cannot, for example, take a picture of someone and then sell it to Apple for use on a billboard, not without a release.