A coalition of digital rights groups is warning that language in a recent federal appellate ruling about Yahoo "threatens significant mischief" to other Web companies.

Public Citizen, joined by the Center for Democracy & Technology, the Electronic Frontier Foundation and the Citizen Media Law Project, filed papers Thursday asking the 9th Circuit Court of Appeals to rewrite its opinion by deleting a passage that could make it costlier for Web sites to defend themselves in court.

The appellate court had ruled that Oregon resident Cynthia Barnes could pursue a lawsuit against Yahoo for breach of contract for allegedly failing to honor a promise to remove a fake profile of her. The profile, which included nude photos of Barnes, was posted by her ex-boyfriend.

Web sites like Yahoo typically have no obligation to delete content posted by users -- even when it's lewd and malicious -- because section 230 of the federal Communications Decency Act says sites are immune from liability for material uploaded by users. But the 9th Circuit found that Barnes' situation falls within an exception to that rule because a Yahoo representative promised that the site would take down the profile.

The civil rights groups agree with the ultimate decision -- that Barnes should have an opportunity to prove that Yahoo broke a promise to her -- but say that the court's language could hurt other Web publishers.

That's because the court characterized section 230 as an "affirmative defense." If that classification holds, it could take Web sites longer to get cases brought against them dismissed.

Yahoo also filed papers asking the court to revise the same portion of the opinion.

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