The National Football League has told two retailers in New Orleans that they can't continue to sell "Who Dat Nation" t-shirts because the Super Bowl-bound Saints team allegedly has exclusive rights to the phrase.

That's got Sen. David Vitter, R-La., and many others in Saints Nation crying foul.

According to the Times-Picayune, "Who Dat" was probably "first heard in minstrel shows in the later 1800s." It's been a rallying cry for Saints fans since the '80s.

But the newspaper says figuring out who does or doesn't own the legal rights to "Who Dat" may not be easy. A local businessman registered the phrase in 1983, but may have let his claim expire. The Saints registered it in 1988, according to the Times-Picayune.

Of course getting any of this sorted out before the Feb. 2 game with the Indianapolis Colts won't be easy — especially not in New Orleans, where court cases are being postponed because of Super Bowl madness.

There's an active discussion about all this on Twitter. Just search #defendwhodat.