Ex-coworker Justin received a hilarious cease and desist letter based on his parody of an ex-gay movement billboard. Great explanation of the failings of wikipedia as a source of legal advice:

You appear to believe that the stolen image is exempt from federal intellectual property laws as a ‘parody’ due to ‘fair use.’ Unfortunately, the intricacies of federal law cannot adequately be covered on ‘Wikipedia’ due to the variety of facts addressed by courts in numerous cases.