You need to respect people's cultures and religions. It is what it is. If Muslims say don't depict the prophet Mohammed - you should respect that. Simple. If they would just do that there wouldn't be any problems.
okay, that's fine. if south park just didn't bother trying to show mohammed, this wouldn't even be an issue or a problem....
....but like other people have said, nothing is off limits on south park. they make fun of everyone. they made fun of every religion in that episode. they had jesus crapping on the american flag in one episode, and in the recent episodes they depicted buddha snorting cocaine. i'm sure a lot of people were offended by those things, and that's understandable.
the difference is, no one is threatening to k!ll anybody when that stuff happens. it's only when the muslims are picked on that people start talking about k!lling. do you see a problem with that?