Special to The Washington Post

Tuesday, January 25, 2005; Page E05

The government`s top lawyer has asked the Supreme Court to overturn the ruling that allowed the makers of online song- and movie-swapping software to stay in business.

The legal brief, filed late yesterday by Acting Solicitor General Paul D. Clement, supports the entertainment industry`s bid to shut down song-swapping networks such as Kazaa and Grokster by suing them for copyright infringement.

On March 29, the Supreme Court is slated to hear arguments in MGM Studios Inc. v. Grokster Ltd., the biggest test of the legality of online file swapping. Lower courts have twice rejected entertainment-industry arguments, ruling that Grokster Ltd. and StreamCast Networks Inc. -- operators of two song-swapping systems akin to the more popular Kazaa -- do not violate copyright law even though people use them for illegal downloads of songs, movies and other copyrighted works.

``The evidence suggests that the respondents have developed vast networks of members whose only common characteristic is apparently their desire to download copyrighted music and movie files without paying for them,`` Clement wrote in the 30-page brief, a filing expressing the government`s opinion. The government is not a party in the case.

At issue is how the lower courts interpreted the Supreme Court`s 1984 Sony Betamax decision. In that case, the court ruled 5-4 that Sony did not violate copyright law by selling the Betamax videocassette recorder -- despite the fact that it could make illegal copies of television shows -- because it also allowed viewers to tape a show to watch later, a legitimate use.

The lower courts applied the ruling in the Grokster case, noting that file-swapping programs can be used for legal purposes, such as distributing a file with the permission of its author.

The government`s brief argues that the lower courts erred in that interpretation. Unlike the Betamax, Clement wrote, Grokster and Morpheus (StreamCast`s file-swapping product) don`t have substantial legitimate uses.

``The overwhelming use of respondents` networks is infringing, and it appears likely that most if not all of respondents` revenues are derived from that infringement,`` Clement wrote.

Mitch Bainwol, chairman of the Recording Industry Association of America, applauded the government brief. ``We`re reviewing the brief in great detail, but we`re delighted and gratified that the U.S. government has chosen to enter this debate in defense of the integrity of property,`` Bainwol said.

RIAA and the Motion Picture Association of America were scheduled to file their own briefs late last night. Those groups announced yesterday that they had retained former solicitor general Theodore B. Olson to help them fight the Grokster case.

Some high-tech firms, including Microsoft Corp. and America Online Inc., and public interest groups such as the Center for Democracy and Technology, have filed friend-of-the-court briefs that ask the court to uphold the earlier Grokster rulings. Those groups say that reinterpreting the Sony decision as the entertainment industry wishes would stunt technological innovation.

``Sony`s protections for companies that develop new products have made possible some of the most important and exciting consumer products over the past 20 years -- from the iPod to instant messaging to the computer itself,`` said Alan Davidson, associate director of the Center for Democracy and Technology.

Operating within the Department of Justice, the solicitor general argues on the government`s behalf before the Supreme Court.

A spokesman for the Justice Department declined to comment for this story.

McGuire is a staff writer for washingtonpost.com.