In a victory for bloggers, other web publishers and newsgroup participants, the California Supreme Court ruled Monday that individual internet users cannot be held liable for republishing defamatory statements written by others.

The unanimous ruling is apparently the first to interpret a 1996 law called the Communications Decency Act as protecting not only providers of content but also online users who redistribute that content, reports CNET. With that law, Congress "has comprehensively immunized republication by individual Internet users," intending "to protect online freedom of expression and to encourage self-regulation," the justices concluded in their majority opinion (pdf).

The case dates back to 2000, when two doctors who operated websites devoted to exposing health frauds sued Ilena Rosenthal, who ran an internet newsgroup for women who have had problems with breast implants; the suit accused her of redistributing libelous content.

A California state court sided with Rosenthal, but an appeals court determined that Rosenthal should be held liable as a "distributor" of the defamatory information - as newspapers and booksellers might be held liable in the offline world.

But merely applying the same approach onto the online world could chill free speech, the state Supreme Court ruled: "The volume and range of internet communications make the 'heckler's veto' a real threat under the Court of Appeal's holding," the justices wrote.