This has been floating around for a couple of days, apparently, but I just saw it: it’s a (warning: profane) video of George Brett cussing out a guy while signing an autograph for him.
As far as can be told of backstory, though, it’s hard to take issue with Brett’s anger, even if he probably would’ve done better keeping it to himself. Seems that this guy has approached Brett on numerous occasions -- over 30 times, actually -- for autographs. Which means he is almost certainly selling them. And, while everyone has to make a living, the grown men who creep athletes in order sell autographs are a special brand of icky. Evidence: this guy was clearly filming the encounter on the sly, likely expecting Brett to go off on him eventually. If you know you’re aggravating someone like that and continue to do it, you probably need to take a good look in the mirror.
Brett, from what I have heard, has always been good about signing for kids or obvious fans. And while the threats and profanity aren’t exactly a great look on him here, the fact that he lost his temper is pretty understandable.