When filming Bruno, were the people aware that they were on camera and that 'Bruno' was actually SBC?

For the most part, people weren't aware. There was a lot of controversy around the time that Borat was released since many of the people filmed were not aware that it was for a comedy movie, nor that the person they were interacting with was an actor in character. The same issue is coming up again with Bruno. Some of the people in the film are upset that they were misled as to the nature of the film.