Universal said it had filed suit against two video sites, announcing legal action against Grouper and Bolt.com Tuesday for hosting pirated versions of its videos. The label is seeking $150,000 per occurrence of copyright infringement, expected to be in the thousands.

Both lawsuits were filed in the U.S. District Court for the Central District of California. They allege that Bolt and Grouper actively participate in the infringement by copying, formatting and distributing material from Universal artists.

Sony Pictures bought Grouper back in August. As the legal owner of the site, the movie studio may now be dragged into the suit as Universal threatened to add it as a defendant. Universal was not available for comment.

In the suit, Universal claimed that Grouper used copyright infringement to become "one of the most prominent and valuable Web sites on the Internet."

Bolt is independently held by Bolt Media. Neither Bolt nor Grouper was available for comment as of press time. Grouper sees about 2 million monthly visitors a month, while Bolt has about 8 million visitors a month. However, both sites pale in comparison to YouTube, which sees about 72 million visitors each month, according to comScore figures.

In North America, Universal counts some of the hottest pop acts in its roster. They include the Black Eyed Peas, Mariah Carey, Eminem, Gwen Stefani, and Kanye West.