The name of the Web site is the first warning of the insanity that lies within. JudasFavre.com speaks for itself. The site is the brainchild of a couple of buddies living in Kewaskum, Wisc, and was launched a little over a month ago to publicize a T-shirt that they created. The shirt has a No. 4 on the front and back, ala Brett Favre's jersey, but it has a different five-letter name on the back. JUDAS. The buddies say that the shirts and the Web site and the bluster are all in fun. Sure. Favre played 16 seasons in Green Bay but is now considering suiting up for Minnesota, news that isn't sitting well with fans of the rival Packers. They were miffed last year when he went to play for the New York Jets, but now, they're downright angry. How could he play for the hated Vikings? How could he wear the loathed purple and gold? Favre is just the latest in the litany of traitors in sports. They have long riled sports fans, adding flavor to the competition and venom to the rivalries. Used to be, players would stay with a team for years, maybe even their entire careers. It was normal to see an athlete retire with the same franchise that drafted them. But even then, there were traitors. Baseball Hall of Famer Johnny Mize became a despised man when he complained about playing time and went from one New York baseball team to the one on the other side of town. The year: 1949. Still, traitors are much more common nowadays because players change teams more often. No matter the sport, it's common to see even the best athletes play for three or four different franchises during their careers. And they aren't beholden to their previous employers. If their best offer comes from a rival team, they think nothing of signing on the dotted line. Their fans, though, think differently. Here's an excerpt of an open letter to Favre written by Karen Waldkirch, a former community columnist at the newspaper in Wauwatosa, Wisc.: "You and I -- we're done," Waldkirch wrote. "In my eyes, you've tarnished your legacy. "I watched you on HBO's Joe Buck Live the other night. ... I listened to you refer to yourself and the Vikings as 'we' and then rolled my eyes when you said that you were 'maybe' coming back to play. "And then, I heard you use the most ridiculous analogy to describe your leaving the Packers -- you compared yourself to Vince Lombardi (how dare you) and him leaving to coach the Washington Redskins. Brett, you're no Vince Lombardi and, last time I checked, the Redskins have never been in the Packers' division." Ouch. But wait, there's more. "All I know is that I'll see you on Nov. 1 at Lambeau Field. ... When you run out on the field, I won't boo -- that's not my style. But when our D-line breaks through and plants you on the tundra, I'll be cheering more loudly than anyone else." That hardly sounds like it's all in fun, and frankly, I don't think most Packer fans are laughing about Favre's flirtation with the Vikings. I suspect most of them are genuinely mad that their guy, their icon, their hero might be playing for a team they so dearly despise. The buddies at JudasFavre.com, by the way, have sold almost a hundred shirts. They shipped them all over the country and even sent a couple to Canada. The shirts come in green or purple for $14.99 with free shipping in the U.S. Visa, Mastercard, Discover and PayPal accepted. If a T-shirt isn't your style, they also have bumper stickers and black armbands with the No. 4. "We have a simple dream," they write. "A dream where Packer fans across the nation turn black to mourn No. 4 turning purple and gold. Regardless of why it's happening, it's just plain wrong. And it makes us very sad." OK, that seems like it's all in fun. If only it wasn't so true.