The Recording Industry Association of America filed a brief Monday asking U.S. District JudgeMarilyn Hall Patel to grant the injunction preventing Napster from “facilitating or assisting others in, the copying, downloading, uploading, transmission or distribution of copyrighted musical works.”

The request was bolstered by declarations filed by Motion Picture Association of America president Jack Valenti and CEO Michael Robertson. Robertson supported the recording industry’s claim that San Mateo, California-based Napster’s music-swapping service was a breeding ground for widespread copyright infringement.

“If Napster can encourage and facilitate the distribution of pirated sound recordings, then what’s to stop it from doing the same to movies, software, books, magazines, newspapers, television, photographs or video games?” Valenti said in his declaration.

While Napster’s central servers can be ordered off-line by the court, distributed network file- sharing systems communicate user-to-user It would require hundreds of thousands of injunctions to halt the widespread trade of content online.

The RIAA sued Napster in December for copyright infringement and related state law violations, asserting that Napster encouraged music piracy via the Internet through its software and computer servers.

Patel ruled May 9 that Napster was not entitled to “safe harbor” as defined by the Digital Millennium Copyright Act because the company “does not transmit, route or provide connections for allegedly infringing material through its system.”

That provision of the act was crafted to protect Internet service providers such America Online and Earthlink from the illegal actions of their users.

A curious new ally in the battle against Napster is Robertson, who last week settled with major recording labels which sought to halt his company’s “Instant Listening Service.”

That feature of allowed users to purchase CDs via the Web site and listen to them online before they were physically delivered to the buyer. The recording industry cried foul, subsequently settled with and entered into a new licensing agreement to allow the service.

Robertson is now concerned that the work of his Web site’s fledgling artists are being given away through Napster.

“Any such distribution would cause potential detriment to both and the artists who upload their music to the Web site,” Robertson said in his declaration.