he struggling recording industry intensified its efforts to combat online piracy yesterday, announcing that it planned to sue individual computer users who share substantial amounts of music online.

Cary Sherman, president of the Recording Industry Association of America, which represents the five major music labels, said that the industry today would start gathering evidence against such individuals by using software to scan the public directories of peer-to-peer networks like KaZaA and Grokster. He said he expected at least several hundred civil and criminal lawsuits would be filed within 8 to 10 weeks.

	Advertisement

Mr. Sherman said that the association's lawyers would file suits against people with the largest selections of online music files — no matter their age. United States copyright laws allow for damages of $750 to $150,000 a song. He declined to specify how many songs on a person's computer would be considered substantial.

"A lot of people think they can get away with what they are doing because peer-to-peer file sharing allows them to hide behind made-up screen names," Mr. Sherman said. "They are not anonymous. The law is very clear. What they are doing is stealing."

The move is the latest step by the recording industry to battle the illegal online downloading it blames for much of its slump. Over the last four years, music sales have plummeted more than 25 percent, Mr. Sherman said. In April, the association began sending warnings to people who offer popular songs for others to copy. It also filed lawsuits against four college students, charging them with copyright infringement and seeking billions of dollars in damages.

The industry was emboldened to make this latest move after the United States Court of Appeals ruled recently that Internet providers were required to release the names of subscribers suspected of illegally sharing music and movie files. It is the hope of music executives that the threat of a lawsuit and public humiliation will deter future online swapping, Mr. Sherman said.

But Fred von Lohmann, a civil liberties lawyer who is a frequent critic of the music industry, faulted the association for its tactics. Mr. von Lohmann, a lawyer at Electronic Frontier Foundation, a nonprofit group in San Francisco, said that a minor could be involved in some cases. He said that such a measure could result in a backlash from angry consumers during a time of economic hardship.

"We think it's a particularly outrageous and ill-advised strategy," Mr. von Lohmann said. "Suing your best customer is always a bad idea. What we need is a way to better pay artists and to make file sharing legal."

Some critics of the music industry said that the industry's decline was related more to overpriced CD's, a lack of new talent and lackluster releases by older artists, rather than downloading.