A state appeals court says a 15-year-old boy whose Web site was flooded with anti-gay slurs and threats can sue a schoolmate who admitted posting a menacing message but described it as a joke.

In a 2-1 ruling Monday, the Second District Court of Appeal in Los Angeles said the violent language of the message - threatening to "rip out your ... heart and feed it to you" and to "pound your head in with an ice pick" - conveyed a harmful intent that is not protected by the right of free speech.

The dissenting justice, Frances Rothschild, said no one who read all the messages posted on the Web site - in which youths tried to outdo the others in outrageous insults - would interpret any of them as a serious threat.

The case is one of the first in California to examine the boundaries between free expression and so-called cyber-bullying. The court majority said a message that threatens physical harm, even if it wasn't meant to be serious, loses its First Amendment protection and can be grounds for a lawsuit.

The plaintiff, identified only as D.C., set up a Web site in 2005 to promote an entertainment career after recording an album and starring in a film. Believing - wrongly, the court said - that he was gay, some fellow students at a Los Angeles high school posted comments that mocked him, feigned sexual interest or threatened violence.

The boy's father said he withdrew D.C. from the school, at the suggestion of Los Angeles police, and moved the family to an undisclosed spot in Northern California. D.C. sued six students and their parents, claiming hate crimes, defamation and intentional infliction of emotional distress.

The ruling involved a claim by one defendant, a 16-year-old identified as R.R., that the suit interfered with his freedom of speech. In a court filing, R.R. said he didn't know D.C. personally but was offended by the Web site's self-promotional tone and "decided to add my own message to the Internet graffiti contest," posing as a parent who was so offended by D.C.'s singing that he wanted to kill him.

He later wrote a letter of apology to D.C. and his family.

State law allows a defendant to win early dismissal of a suit that chills free speech on a subject of public interest and has little chance of success. The court majority said the law didn't apply to D.C.'s suit because R.R.'s message contained threats and was unrelated to any issues of public interest.

Rex Beaber, lawyer for R.R. and his parents, said Tuesday that he would appeal to the state Supreme Court. No reasonable person could have interpreted the message as a serious threat, he said, and the ruling "undermines the First Amendment protection for unpopular speech."