Variety.com - Inside Move: 'South Park' feeling some celeb heat?: "'So, Scientology, you may have won THIS battle, but the million-year war for earth has just begun! Temporarily anozinizing our episode will NOT stop us from keeping Thetans forever trapped in your pitiful man-bodies. Curses and drat! You have obstructed us for now, but your feeble bid to save humanity will fail! Hail Xenu!!!'
The duo signed the statement 'Trey Parker and Matt Stone, servants of the dark lord Xenu.'"
Update (from Tom): This is way funnier if you read the Wikipedia entry for Xenu.