Its fun as hell actually, especially with flash. Ask jnovak about when I totally short circuited a group of 50 year old dSLR users by walking into the middle of them and taking a strait on photo of one of them with flash.
I watched that video and came to the conclusion that photographer is a royal ass, did you notice how he did not take a photo of that big bald dude only some of the more vulnerable people? That style might work in NY, try it around here and your most likely going to get into a conflict. His photo’s might be interesting but, I don’t think as photographers we have the right to scare the crap out of people to take a picture.