The number of books threatened with removal from American library shelves dropped to an all-time low last year. “Challenges have gone up and down over the past few years, but overall have dropped by more than half since Banned Books Week was started. Judith Krug, director of the ALA’s Office for Intellectual Freedom, cited a couple of possible factors for the decline: Librarians are better prepared to organize community support on behalf of a book, and would-be censors are focusing more on online content.”