Justin Watt, a gay blogger, has riled up Exodus International, the "ex-gay" folks, with his parody of their billboard. Watt took a photo of the billboard, aimed at recruiting gays for the "cure," and altered it so the roles of gays and straights were reversed. The Exodus lawyers failed to appreciate the joke and sent Watt a cease-and-desist letter.
Now, it may be turning into a First Amendment case as the ACLU has taken up the cause claiming, correctly in my view, that this parody is constitutionally protected speech.