In the other parts he is filming in public and is getting the same reactions.

  Part 2: http://www.youtube.com/watch?v=7bT1ZfRtrJc
  Part 3: http://www.youtube.com/watch?v=QHG9ouQ17-M

But I'm not sure it's the size of the camera. Most of the people are not bothered by big cameras hanging everywhere.

Maybe it's because they don't trust the intents of the guy who is filming.