SAN FRANCISCO — A federal appeals court has extended the First Amendment protections of do-it-yourself online publishers.

A three-judge panel of the 9th U.S. Circuit Court of Appeals ruled 2-1 that online publishers can post material generated by others without liability for its content — unlike traditional news media, which are held responsible for such information.

"It clarifies the existing law," said Eric Brown, who represented the defendant in the suit. "It expands it in the sense that no court had really addressed bloggers, list serve operators and those people yet, certainly not on the level of the 9th Circuit Court."

Blogs, short for Weblogs, are online diaries updated frequently by tech-savvy writers who use the medium to comment on current events and everyday life.

Online publishers and free-speech advocates lauded the panel's decision.

"The decision is a real victory for free speech," said Jeralyn Merritt, a lawyer and blogger who manages talkleft.com, a Web site about crime-related news and politics. "Now we can publish information we receive from someone else without fear of getting sued."

Merritt said it would be impossible to monitor the nearly 200 messages posted on her site every day.

"I can't be responsible for the content of those comments," she said.

The decision recently was the most discussed topic according to Daypop.com, a current events search engine that crawls the Web and reflects its collective conscience, identifying the topics that are generating the most interest in the blogging world.

The June 24 decision was based on the 1996 Communications Decency Act, Brown said.

Other cases have said commercial service providers on the Internet are not responsible for information posted by a third party. And this decision says noncommercial Web site hosts are only liable when they post information that a reasonable person would have known wasn't meant to be published.

This case involved a North Carolina handyman, Robert Smith, who said he'd overheard a lawyer, Ellen Batzel, say she was the descendent of a top Nazi politician. Smith said Batzel also had what looked like old European paintings in her house.

Smith e-mailed Ton Cremers, who runs the Museum Security Network, sharing his suspicion that the paintings in Batzel's house were looted Nazi goods. Cremers' Web site tries to find stolen artwork by sending information to museums and law enforcement personnel.

Cremers posted Smith's e-mail to his listserve — and Batzel saw it.

She disputed the claims, sued Smith, Cremers and the Museum Security Network for defamation, and won.

Cremers appealed, and the panel majority found that "a service provider or user is immune from liability when a third person or entity that created or developed the information in question furnished it to the provider or user under circumstances in which a reasonable person in the position of the service provider would conclude that the information was provided for publication on the Internet."

The case has been sent back to the trial court to determine whether the operator should have known the information was not intended for online publication.

It was significant that even though Cremers made minor edits to Smith's message, he was still entitled to the immunity, said Lee Tien, senior staff attorney at the Electronic Frontier Foundation, a nonprofit concerned with the protection of digital rights.

"It was a reaffirmation of this trend in other cases," said Tien. "You don't have to be a passive conduit to have this protection."

The decision is a relief for bloggers and other online publishers.

"We write for the enjoyment of it," said Merritt. "If we would get sued, I'm not sure it would be worth it."