Books are not banned because they are inherently dangerous, or actually malicious, or even purposefully damning. Books like those are already avoided by those who do not agree with them. No, books are banned because there are people with power who fear the power of words. They fear the ideas and challenges put forth by such "dangerous" books. They hate the thought that their ideals could very easily be questioned or destroyed by simple ink and paper. And they wish to control, so they hate and they ban.