Free speech is not to be regulated like diseased cattle and impure butter. The audience (in this case the judge or jury) that hissed yesterday may applaud today, even for the same performance.

William O. Douglas (1898-1980) US Supreme Court justice (1939-75)

Dissent, Kingsley Books, Inc. v. Brown, 354 U.S. 436, 447 (1957)

The court ruled 5-4 to allow banning the sale of obscene books.