Reason.com offers a lengthy interview with Trey Parker and Matt Stone, the creators of South Park. In it they discuss the series' satire of the left and the right, and their life long quest for nonconformity. Particularly interesting is the discussion of Comedy Central's maneuverings regarding depictions of Muhammad and Scientology.
This quote from Matt Stone sums things up nicely:
I had Birkenstocks in high school. I was that guy. And I was sure that those people on the other side of the political spectrum were trying to control my life. And then I went to Boulder and got rid of my Birkenstocks immediately, because everyone else had them and I realized that these people over here want to control my life too. I guess that defines my political philosophy. If anybody’s telling me what I should do, then you’ve got to really convince me that it’s worth doing.