I was once listening to a pastor talk about watching movies with his kids. He advised parents always pre-screen movies, even G-rated ones, to be sure the children in the movie never disobey or disrespect their parents. He believed that, even if the parents are wrong, if he isolates his children from any negativity towards parents, he will remain in control.Book banning satisfies their need to feel in control of their children's lives.
Ugh, as a Christian raised in church, my parents had no respect for these kinds of people and neither do I. Sheltering is nothing more than fear and handicap. My parents had no problem playing Total Recall or Die Hard in front of me as a kid, and I turned out alright. Now this doesn't mean my son is going to be watching Salo as a toddler, but he won't be completely unaware of the world.