A quick Googling didn't turn up anything, but I'd be shocked if Matt and Trey supported SOPA. Comedy Central, maybe, but not them.

Allegedly from the South Park Studios FAQ: (http://www.idealog.us/2006/10/matt_and_trey_w.html):

> Matt and Trey do not mind when fans download their episodes off the Internet; they feel that it’s good when people watch the show no matter how they do it.