One thing that has puzzled me about the threats to Trey Parker and Matt Stone is the apparent lack of consequences. Does the posting about them winding up like Theo Van Gogh count as a threat? Um, well, doesn't it? Sure, Revolution Muslim has a measure of deniability. It's like "Will no one rid me of this meddling priest?" or "You know what happens to nosy fellows? Wanna guess?" It's not 100% explicit, but there must be enough to warrant investigation. But I haven't really heard about law enforcement being on this. And of course, Comedy Central caved, hence doing 90% of the work of terrorism on themselves.
Not too surprisingly, the incident has been taken in some quarters as evidence that the Saracen enemy has stepped up their invasion. Glenn Greenwald has a refreshing corrective, pointing out that RM is an extremist website from any community's standpoint. (And bizarrely enough, founded by a convert from a similarly militant branch of Judaism.) And there's a partial list of the other people in America who have made threats and called for censorship. Quite a popular pastime.