"If the First Amendment means anything, it means that a state has no business telling a man, sitting alone in his house, what books he may read or what films he may watch. " -- US Supreme Court Justice Thurgood Marshall (b. 1908-07-02, d. 1993-01-24)
"You can't win, Book Banner. If you censor these books they will become more powerful than you can possibly imagine!" -- from Unshelved, 2002-10-16 (comic within a comic; Dewey as a librarian Obi-Wan Kenobi)
"Because they never learn. The inevitable result of trying to ban something -- book, film, play, pop song, whatever -- is that far more people want to get hold of it than would ever have done if it were left alone. Why don't the censors realise this?" -- Philip Pullman, "The censor's dark materials", Guardian, 2008-09-29
[I didn't mean to let so much of Banned Books Week slip past before posting a relevant quote. Whoops.]