In papers filed in a New Jersey state court last week, Wikipedia argues that it is immune from liability under the federal Communications Decency Act. That law generally provides that Web sites can't be sued for comments posted by users.

"It's clearly the case that we have a statutory immunity and I expect that we will demonstrate that to the court," said Mike Godwin, general counsel at Wikipedia's parent company, the Wikimedia Foundation.

The case stems from a 2006 article about Bauer's company, the Barbara Bauer Literary Agency. She alleged in her lawsuit that the Wikipedia article libeled her by calling her "The Dumbest of the Twenty Worst" literary agents and asserting that she has "no documented sales at all."

In its court papers, Wikipedia disputed that characterization of the article, asserting that the article in question said Bauer's agency was "listed by Writer Beware ... as one of the twenty worst literary agencies," but not as "the dumbest of the worst." Wikipedia also stated the article said that most of the 20 agencies "have virtually no documented and verified sales at all," but still charge writers administrative fees or editing fees.

The article itself was removed from the site by volunteer editors, Godwin said.

Bauer, based in Matawan, N.J., sued the Wikimedia Foundation for libel, and also sued individual bloggers who allegedly called her one of the worst 20 agents on other sites.

There are few, if any, other instances where Wikipedia has been sued for libel in the U.S.--despite the fact that all content on the site is submitted by users and edited by volunteers. But even without a clear track record of lawsuits against Wikipedia, other court decisions interpreting the Communications Decency Act give the site solid cause for optimism that the case will be dismissed, according to Eric Goldman, director of the High Tech Law Institute at Santa Clara University. "There is no doubt that Wikimedia qualifies for (immunity) for any claims based on user submissions or edits to Wikipedia, and I would expect any associated lawsuit against Wikimedia alleging libel to be tossed quickly," he said.

Wikipedia also argues that the case should be dismissed because some of the alleged comments complained about are opinions, which courts have said can't be considered defamatory. "Calling people 'dumb' is not libelous," said Matt Zimmerman, a lawyer with the Electronic Frontier Foundation, which is part of Wikimedia's legal team.