The last week of September is traditionally Banned Books Week in the United States.
It doesn't take much to become a banned book. Merely, the word of an uninformed bigot and the tacit support of a silent administrator can bring public censure to a work of art.
Most of my favorite authors are banned somewhere in the US. Most of Twain, a bit of Hemingway, Fitzgerald, Dahl, Capote, Alice Walker, and Webster's Dictionary. You could posit that a book not on the list is not worth the trouble of reading.
For further info check out Google's Banned Book link
Stamp out prejudice, Read.