O'Reilly used terms like "Diller the Killer" and called Dr. Diller a "mass murderer"in referring to the doctor who performed late term abortions, legal under the law. When Dr. Diller was murdered, O'Reilly broadcast the lame excuse that, while he deplored the murder, he had nothing to do with it.
There is an existing court decision concerning Paladin Press which said, in essence, that a person could not use inflammatory language which elicited a violent action as a response and hide behind the First Amendment. Since Fox "News" was immediately responsible for this action, they forfeited their right to broadcast under the Federal Communications Act.