You have to remember, something that these guys LOVE to do is screw with the audience!
Do you remember that cliff-hanger, where Cartman's father's identity was going to be revealed in the next episode? And instead of showing that episode, they did a "Terrance and Phillip Special?"
I read an interview where one of the guys said that they were just making a joke, but they started getting death threats!
Mark
Theirs and Comedy Central's voice mail boxes were overloaded with hate and threats. Some of the calls were so over the top that Comedy Central ran them as commercials for South Park.
I remember the Cartman's dad fiasco. Comedy Central ran all the complaint calls to promo the actual episode. It was hillarious. You've gotta give TP and MS credit for being the most topically funny guys around. From the Janet Reno Easter Bunny episode to Chris Reeves on Stem Cell Research, it's always funny.