Filed at 5:35 p.m. ET

WASHINGTON (AP) -- Music companies tried to persuade a judge Friday to let them obtain the names of people suspected of trading music files online without going to court first, a move that could dictate how copyright holders deal with Internet piracy in the future.

Internet service provider Verizon is resisting the music industry's subpoena, saying that it could turn Internet providers into a turnstile for piracy suits and put innocent customers at risk.

U.S. District Judge John D. Bates, who heard the case, lamented ambiguities in the Digital Millennium Copyright Act, which was enacted to uphold copyright laws on the Internet while shielding technology companies from direct liability.

Congress ``could have made this statute clearer,'' Bates said. ``This statute is not organized as being consistent with the argument for either side.''

Bates said he would try to rule quickly, but lawyers for both sides had no guess of when a decision might arrive.

The subpoena hearing, which is normally a tame affair, was contentious because the music industry sees it as a test case. If it succeeds, it plans to send reams of cease-and-desist letters to scare file-swappers into taking their collections offline.

Until now, copyright holders have relied on requests sent to Internet providers to take action on their own against suspected pirates. Almost all Internet providers forbid sharing copyrighted material without permission.

But that can take a lot of time, and makes copyright holders reliant on Internet providers to enforce the law. Internet providers do not always respond as well or as quickly as music and movie publishers would prefer. They think individual letters from the maker itself might work better.

``Wouldn't that be a lot easier way to let people know that they are in fact not anonymous and there could be consequences?'' asked Cary Sherman, RIAA's general counsel.

Verizon said that since the hundreds of songs up for trade by the anonymous Verizon customer at the center of the case sit on the person's computer rather than Verizon's network, it is not required to automatically give up the subscriber's name.

``Verizon was a passive conduit at most,'' said Eric Holder, a former Justice Department prosecutor who represented Verizon. Holder said the music industry's strategy could create a contentious relationship between Verizon and its customers and put the Internet provider in the position of handing over names to the music companies without a judicial determination of piracy.

``We also don't want to be the policeman in this process,'' Holder said.

Lawyers for the recording industry rejected Verizon's arguments that it had little obligations in the process. Industry lawyer Donald Verrilli said no type of service provider is exempt from having to identify a potential music pirate, no matter where the songs sit.

Verrilli also dismissed Verizon's position that the Internet provider's customers have a right to privacy.

``You don't have a first amendment right to steal copyright works,'' Verrilli said.

The judge disagreed with Verrilli's assumption that the works were stolen.

``Here, there's only an allegation of infringement,'' Bates said.

Bates gave few hints as to how he might rule. He asked many, detailed questions of both sides. He called some Verizon positions vague, but showed little patience with other arguments advanced by the music industry and movie studios, which also argued on behalf of music publishers.

Through programs like Kazaa, Morpheus and Gnutella, a person can find virtually any song or movie -- sometimes even before it's released in stores -- and download it for free. On a typical afternoon, about 3 million people were connected on the Kazaa network and sharing more than 500 million files.