Representatives of the movie, recording and software industries said yesterday that preserving a law banning technologies that let people copy DVDs and other digital entertainment is necessary to stop rampant piracy, even if it means that consumers cannot make copies for their personal use.

At a lively hearing of the House Energy and Commerce Committee's subcommittee on commerce, trade and consumer protection, the lobbyists said changing the law and allowing such technologies could cripple the multibillion-dollar entertainment industry, chill creative innovation and cost jobs.

But proponents of a change scoffed at such claims. They said the 1998 Digital Millennium Copyright Act went too far to protect those who create digital media, and instead punishes people who simply want to enjoy music or movies in different locations by having more than one copy.

The sparring was over one of the most difficult conundrums of the digital age: how to prevent the wholesale theft of copyrighted works -- which new technology can enable -- while letting consumers benefit from the convenience that such technology allows.

To the entertainment industry, which is at war against piracy on file-sharing networks and elsewhere, the only solution is to put technology into their products to prevent copying, and then outlaw anything that seeks to break that technology.

Jack Valenti, who heads the Motion Picture Association of America, said current copy-protection technology cannot distinguish between the pirate who wants to send out thousands of digital copies around the Internet, and the CD or DVD purchaser who wants another copy for the car or the house in the country.

"Once you allow one person to break [protection technology], you allow everyone to do it," Valenti said.

That is the philosophy behind the current law, which a bipartisan group of House members seeks to change. In their view, individuals have long-standing rights to "fair use," which allows protected works to be shared for personal, noncommercial use.

"User rights have been eroded," said Rep. Rick Boucher (D-Va.), who with 15 members from both parties is sponsoring a bill to loosen DMCA restrictions.

Rep. John T. Doolittle (R-Calif.), one of the bill's co-sponsors, waved his Apple iPod for committee members to see and said he failed to grasp when he voted for the DMCA in 1998 that it would restrict his rights to make use of music he had legally purchased.

"We went way overboard," he said. "It needs to be corrected."

The law has already led to a federal judge blocking DVD-copying software developed and sold by 321 Studios Inc. of St. Charles, Mo.

"In three years we created almost 400 jobs and were on track to achieve $100 million in sales," 321 Studios chief executive Robert Moore said in prepared testimony for the committee. "Today, I appear for my family and the fewer than 60 remaining employees of a company on the brink of annihilation."

Proponents of changing the law argue that efforts to stop illegal copying should focus on the conduct of pirates, not the underlying technology that provides law-abiding users with rights and benefits.

"It's just like a fork," said Gary J. Shapiro, head of the Consumer Electronics Association, many of whose members make products that allow digital copying, mixing and editing. "You can eat with it, and you can use it to kill someone." Banning the fork, he said, makes no sense.

Other witnesses said that the ban on copying is making it harder for libraries and other educational institutions to make selected use of digital works for long-distance learning.

Cary H. Sherman, president of the Recording Industry of America, said that the DMCA simply outlawed hacking tools.

But Rep. Joe Barton (R-Tex.), chairman of the full House Energy and Commerce Committee, said the DMCA was too restrictive.

"After I buy a CD or a movie, it is mine once I leave the store," he said, as long as he does not break copyright law by selling copies.

Rep. John M. Shimkus (R-Ill.) asked movie industry representatives whether the DMCA would prevent a tool that would allow him to edit out scenes containing "smut" that he does not want his children to see.

An MPAA lawyer said it would, but that technology could allow him to fast-forward past those scenes.

"But first I'd have to see it," Shimkus replied.

Former representative Al Swift, a Washington state Democrat, said he is a former disc jockey and a music lover who enjoys taking individual songs from CDs and making compilations that he gives to friends.

Swift said the law treats most U.S. consumers as pirates, which they are not.

"The American consumer is no threat to these industries," Swift said. "I own 3,000 CDs at an average price of . . . $13 each. I am, like other American consumers, a profit center for these businesses. It is about time they treated us with a little respect."

To date, there is no companion bill in the Senate.