I have to wonder if there's anything you could put in a book that would really, truly need to be banned. Some peice of knowlege or an idea so destructive that the world really is better off not knowing about it.

One of my good friends is from Germany, where one must have at least graduated high school (I believe, either that or have a university degree) before being allowed to purchase/read Mein Kampf. This is not because the ideas are so destructive, per se, but because Hitler was just so damned persuasive of a speaker/writer, and anyone with a lesser education would not be able to think about it in context as completely as someone with higher education would.

Or at least that's my interpretation of that particular bit of law, and I'm sure it also has to do with the whole WWII sensitivity thing.