Barrett V. Rosenthal

Barrett v. Rosenthal is a 2006 California Supreme Court case concerning online defamation. The case resolved a defamation claim brought by Stephen Barrett, Terry Polevoy, and attorney Christopher Grell against women's health advocate Ilena Rosenthal and several others. Barrett and others alleged that the defendants had republished libelous information about them on the internet. In a unanimous decision, the court held that Rosenthal was a "user of interactive computer services" and therefore immune from liability under Section 230 of the Communications Decency Act.

The California Supreme Court reversed a judgment by the California Court of Appeals, First District, which would have allowed a trial on one of the defamation claims. The lower court's decision was the first opinion to break from Zeran v. America Online, Inc. by holding that Section 230 immunity was not absolute for common law distributors. In reversing the Court of Appeals, the California Supreme Court reaffirmed Zeran and directed that all claims against the defendants be dismissed.