Less than a month after "South Park" creators Matt Stone and Trey Parker were forced to apologize for lifting material for a spoof of "Inception" from the website CollegeHumor, the show is again facing accusations of content theft.

The producers of the animated hit, including Viacom and Comedy Central, are being sued for allegedly ripping off a copyrighted music video for the viral phenomenon "What What (In the Butt)."

The video was produced by Brownmark Films based on a song by Samwell. Released in 2007, it became a massive hit and was featured on PerezHilton.com and VH1's Best Week Ever.

The video has been downloaded over 33 million times on YouTube. According to the site, it's one of the most watched music videos of all time.

In 2008, South Park aired a re-creation of the video in the episode 'Canada on Strike,' featuring the "South Park" character Butters in place of Samwell.

Video: South Park, "What What (In The Butt)" Parody

On Friday (Nov. 12), Brownmark Films filed a copyright infringement lawsuit in U.S. District Court in Wisconsin, alleging that the infringement is "willful, intentional, and purposeful, in disregard of and indifferent to the rights of Brownmark."

Brownmark is seeking a permanent injunction and maximum statutory damages.

In response to the lawsuit, Comedy Central sent The Hollywood Reporter its response: "Courts have consistently recognized that parody enjoys broad protections under the First Amendment and the Copyright Act. We believe 'South Park's' parody of the 'What What (In the Butt)' viral music video... is fully protected against any copyright infringement claims under the fair-use doctrine and the First Amendment and we plan to vigorously defend those rights."

Curiously, in a 2008 interview with Brownmark founders Bobby Ciraldo and Andrew Swant on the website blogcritics.org, the duo said they were "completely surprised by the 'South Park' homage" adding that they "sent Trey and Matt a thank-you e-mail the next day."