This ESPN article documents the current trendy topic of who owns the phrase "Who Dat"? As the article points out, the NFL has sent local New Orleans stores cease and desist notices claiming the "Who Dat" trademark as their own, at least as it related to the New Orleans Saints. Simply put, the NFL is claiming they own the New Orleans Saints, therefore they own the term so often used to describe them. The timing of these letters being sent, right before the SuperBowl, couldn't be more infuriating. Clearly the NFL is out to capitalize on the current merchandise gold mine that is the Saints, and greedily make a buck that doesn't belong to them. Laying claim to Who Dat is a shameful ploy by the league, and I'm glad to hear that we're out there fighting to place the term where it belongs: in the ownership of the fans.
Here's another great take on the topic by a Saints fan: Washington Post online article