Bill Maher and Larry Charles designed their new movie “Religulous” as an argument; it’s intended to raise questions about the value of faith in modern times and get people thinking – really thinking – about the things they say they believe. It’s almost certainly going to get people talking, and then talking very loudly, and then shouting at each other in the parking lot. This isn’t the first time a documentary has been built to cause offense. Sometimes, movies have to slap people across the face just to get their attention. Here are seven other non-fiction features that confronted audiences with disturbing images and ideas, and dared them not to see. Click on the first thumbnail below to get started.-- by Norman Wilner