The bill, approved by Congress on Tuesday, is written so broadly it could make a federal felon of anyone who has even one copy of a film, software program or music file in a shared folder and should have known the copyrighted work had not been commercially released. Stiff fines of up to $250,000 can also be levied. Penalties would apply regardless of whether any downloading took place.

If signed into law, as expected, the bill would significantly lower the bar for online copyright prosecutions. Current law sanctions criminal penalties of up to three years in prison for "the reproduction or distribution of 10 or more copies or phonorecords of one or more copyrighted works, which have a total retail value of $2,500 or more."

The bill could be used to target casual peer-to-peer users, although the Justice Department to date has typically reserved criminal charges for the most egregious cases.

Invoking a procedure used for noncontroversial legislation, the U.S. House of Representatives on Tuesday overwhelmingly approved the measure, called the Family Entertainment and Copyright Act. Because the bill already has cleared the Senate, it now goes to President Bush for his signature.

Enactment of these criminal penalties has been a top priority this year for the entertainment industry, which has grown increasingly concerned about the proliferation of copyrighted works on peer-to-peer networks before their commercial release.

"This bill plugs a hole in existing law by allowing for easier and more expeditious enforcement of prerelease piracy by both the government and property owners," said Mitch Bainwol, chairman of the Recording Industry Association of America. "We applaud Congress for taking this step."

The bill's supporters in Congress won passage of the prison terms by gluing them to an unrelated proposal to legalize technologies that delete offensive content from a film. That proposal was designed to address a lawsuit that Hollywood studios and the Directors Guild of America filed against ClearPlay over a DVD player that filtered violent and nude scenes. (ClearPlay had gained influential allies among family groups such as the Parents Television Council and Focus on the Family.)

Peer-to-peer network operators criticized Congress' vote on Tuesday.

"It appears the entertainment industry has once again gotten Congress to use taxpayer dollars to clean up their internal problems," said Michael Weiss, chief executive of StreamCast Networks. Weiss, whose company distributes the Morpheus client, says that many movies and music files that find their way to the Internet early are provided by insiders in the entertainment industry.

Adam Eisgrau, executive director of P2P United, a peer-to-peer software industry association, said his group remains "concerned that the nature of the punishment remains radically disproportionate to the technical crime."

Added Peter Jaszi, a professor at American University who specializes in copyright law: "I don't think this is an approach that is well calculated to create respect for the system."

The criminal sanctions embedded in the Family Entertainment and Copyright Act have been inching their way through Congress since
late 2003. An earlier version was drafted in response to footage of "Star Wars: Episode II," "Tomb Raider" and "The Hulk," reportedly surfacing on peer-to-peer networks before their theatrical release. A few months earlier, the major studios had halted their normal practice of sending DVD "screeners" to Academy Award judges.

"I am pleased that the House has passed this bill, which takes us forward in the fight to prevent the most egregious form of piracy--the illegal copying and unauthorized distribution of 'prereleased' works," Sen. Dianne Feinstein, a California Democrat, said after the vote.

Public interest groups have criticized the measure, saying that the strict criminal sanctions do not take "fair use" rights into account. Other sections of the bill create new federal prison terms of up to three years for anyone who unlawfully records a movie in a theater and provide copyright holders with new civil remedies for prerelease movies, music and software that is registered with the U.S. Copyright Office.

Under a 1997 law called the No Electronic Theft Act, copyright infringement has long been a federal crime when the value exceeded $1,000, even if no money changed hands. But Hollywood and the RIAA have argued that it has been too difficult to convince the Justice Department to prosecute people who have been distributing prerelease movies and music.

CNET News.com's John Borland contributed to this report.

update File-swappers who distribute a single copy of a prerelease movie on the Internet can be imprisoned for up to three years, under a bill that's slated to become the most dramatic expansion of online piracy penalties in years.