Kick them in the public relations. And maybe have a Senator on your side. The NFL is backing off its actions (though no word on their claim) to force local merchandisers to stop selling and producing "Who Dat" merchandise. This announcement came quick on the heels of a statement from "Diaper" David Vitter daring the NFL to sue him for printing "Who Dat" t-shirts.
But here's the reality. David Vitter doesn't make that dare without some serious outrage in his state, and nationwide. That outrage was fed by lots of people both on traditional and new media, making a stink over an issue that frankly, no one individually had the money to fight over. Local retailers don't have the resources to go to court over an issue which has a pretty limited life span. Even if the Saints win the Superbowl, no one outside the Saints' fan base is going to be buying "Who Dat" gear in two months. The NFL counted on that and figured--rightly so--that they could scare locals out of the marketplace with a cease and desist letter, because this is the kind of case where the facts aren't as important as the resources each side can marshal. Sure, a local t-shirt maker could win, but by the time they did, they'd be financially ruined, and they know it.
What was different this time was the volume of the response. The NFL found itself in a shitstorm of bad public relations--a storm the Saints organization managed to dodge, somehow, though they're as much to blame as the NFL--and it didn't want this being an issue going into the crown jewel of its season, a Superbowl between the two best teams all year. They were hurt in about the only way you can hurt a big corporation--in its reputation.
I suspect it will be a temporary victory. At some point, the Saints and the NFL will seek to enforce that trademark, and a friendly judge will do so because no one will have the resources to stand up against them, and because it will happen in the off-season, or when the Saints aren't media darlings anymore, the outrage won't be as loud or widespread.
But for now, it's a win, and I love it. Still not buying any NFL merchandise though/