"Censorship grows out of fear and, because fear is contagious, some parents are easily swayed. Book banning satisfies their need to feel in control of their children’s lives. This fear is often disguised as moral outrage. They want to believe that if their children do not read about it, their children will not know about it. And if they do not know about it, it will not happen."
Makers has an interview with Blume on the reason given when her book, Are you There God? It's Me, Margaret was banned in her children's school. Find it through this link to the Makers page.