Sept. 29 marks the beginning of the American Library Association's annual "Banned Books Week," a commemoration of all the books that have ever been removed from library shelves and classrooms. Politics, religion, sex, witchcraft — people give a lot of reasons for wanting to ban books, says Judith Krug of the ALA, but most often the bannings are about fear.

"They're not afraid of the book; they're afraid of the ideas," says Krug. "The materials that are challenged and banned say something about the human condition."