Per the article, because he wanted to shine light on the fact that you play by different rules if you are wealthy.

From the article:

Parr’s experiment and documentary raises questions, of course, about who gets to have privacy in America. A wealthy enclave has set up the legal and surveillance infrastructure to be able to prevent being mapped. The rest of us, meanwhile, are subject to all sorts of surveillance by our neighbors and law enforcement. “The only reason it’s set up this way is because it’s such a wealthy community,” Parr said. “I know that I was able to do this, but I don’t know if I should be able to do this, and that’s kind of the question that I wanted to tackle. The YouTube comments are pretty crazy man. They’re all over the place. They’re very split 50/50 on that question.”

Seems like a pretty worthy activity to me.