The site late last week began purging copyrighted material from Comedy Central, including clips from YouTube stalwarts like “The Daily Show With Jon Stewart", “The Colbert Report” and “South Park.”

The action was “a result of third-party notification by Comedy Central,” according to one such e-mail message sent to a YouTube user, Jeff Reifman, who broke the news on the Web site NewsCloud.

A week earlier, nearly 30,000 clips of TV shows, movies and music videos were taken down after the Japanese Society for Rights of Authors, Composers and Publishers cited copyright infringement.

The situation is tricky for a network like Comedy Central, part of Viacom. Its audience is young and technologically sophisticated, and Comedy Central stars in the past have used YouTube and clip services to interact with their audience.

Youtube isn't the only site that's starting to crack down on copyright infringement either. Myspace is going to clamp down on infrigement through a deal with digital entertainment company, Gracenote. The agreement will detect and block copyrighted music that is placed on its site.

For both sites the move is in response to efforts to create deals with media firms and the legal owners to share revenues.