Craigslist should not be held liable for discriminatory housing ads posted on the popular Web site, a federal appeals court ruled Friday.

The decision by the 7th U.S. Circuit Court of Appeals is a win for San Francisco-based Craigslist, an online network of classified ads and forums on which more than 30 million notices are posted every month, according to the ruling.

It is also a triumph for Internet sites that depend on user-generated content and for foes of legal boundaries for the Web, experts said.

The ruling means "the soapbox is not liable for what the speaker has said," said Kurt Opsahl, a senior staff attorney with the Electronic Frontier Foundation, a San Francisco-based nonprofit organization that advocates for free speech online.

The lawsuit, filed by a consortium of Chicago attorneys in February 2006, accused Craigslist of violating federal housing laws by publishing more than 100 ads that excluded potential buyers or tenants on the basis of race, gender or religion.