The FBI ordered wikipedia to remove its seal from the article there about the bureau. It threatened to litigate. Unfortunately for the FBI, the law it cited is the one that forbids making counterfeit badges, and Wikimedia's lawyers mocked them in its response.

John Schwartz in the NYT: "Many sites, including the online version of the Encyclopedia Britannica, display the seal. Other organizations might simply back down. But Wikipedia sent back a politely feisty response, stating that the bureau's lawyers had misquoted the law. 'While we appreciate your desire to revise the statute to reflect your expansive vision of it, the fact is that we must work with the actual language of the statute, not the aspirational version' that the F.B.I. had provided."

The part that's hard to understand is why the FBI would seek to abuse the law in such petulant fashion, knowing that it will be subject to public ridicule for its actions.

F.B.I., Challenging Use of Seal, Gets Back a Primer on the Law [NYT via submitterator. Thanks, OdMeadhbh]