California Code, Civil Code - CIV § 48.5

(1) The owner, licensee or operator of a visual or sound radio broadcasting station or network of stations, and the agents or employees of any such owner, licensee or operator, shall not be liable for any damages for any defamatory statement or matter published or uttered in or as a part of a visual or sound radio broadcast by one other than such owner, licensee or operator, or agent or employee thereof, if it shall be alleged and proved by such owner, licensee or operator, or agent or employee thereof, that such owner, licensee or operator, or such agent or employee, has exercised due care to prevent the publication or utterance of such statement or matter in such broadcast.

(2) If any defamatory statement or matter is published or uttered in or as a part of a broadcast over the facilities of a network of visual or sound radio broadcasting stations, the owner, licensee or operator of any such station, or network of stations, and the agents or employees thereof, other than the owner, licensee or operator of the station, or network of stations, originating such broadcast, and the agents or employees thereof, shall in no event be liable for any damages for any such defamatory statement or matter.

(3) In no event, however, shall any owner, licensee or operator of such station or network of stations, or the agents or employees thereof, be liable for any damages for any defamatory statement or matter published or uttered, by one other than such owner, licensee or operator, or agent or employee thereof, in or as a part of a visual or sound radio broadcast by or on behalf of any candidate for public office, which broadcast cannot be censored by reason of the provisions of federal statute or regulation of the Federal Communications Commission.

(4) As used in this Part 2, the terms “radio,” “radio broadcast,” and “broadcast,” are defined to include both visual and sound radio broadcasting.

(5) Nothing in this section contained shall deprive any such owner, licensee or operator, or the agent or employee thereof, of any rights under any other section of this Part 2.