Why are radical Muslims so outraged by South Park?

Okay first off I can understand how they might not like showing Muhammad in the show. But I mean they showed Buddha doing cocaine and they make fun of Jesus and Satan all the time. Im not saying its right but thats not a reason to hurt anybody. I mean, I am Catholic and my friends joke about my priest doing stuff to me, but I just laugh and ignore it. No offense but to me, this kind of reinforces the stereotypes about Muslims. I dont hate Muslims, but I am getting a little almost paranoid at this point, and this sure doesn't show a positive message about some Muslim groups. Jews, Gays, Catholics, Mexicans, Blacks, Scientologists, Mormons, and all sorts of people are ripped on in that show, so why have none of these people sent them threats. Not all Muslims, but some organizations. I try to not stereotype, but in this case I kind of am.