A Miami-Dade Circuit Court judge on Thursday ordered America Online and Yahoo! to divulge the identity of an anonymous message writer sued for defamation by Fort Lauderdale businessman J. Erik Hvide -- saying Hvide has every right to face his accuser.

Although the issue of releasing identities behind screen names has been at the core of much legal debate, attorneys in this case and national experts believe Circuit Judge Eleanor Schockett's ruling is the first court order to question whether ``John Doe'' has a constitutional right to anonymous speech on the Internet.

``Give them anonymity and nothing holds them back,'' she said. ``That's why the Ku Klux Klan wears hoods.''

Schockett deemed Hvide's right to face his accuser in court more important than the defendant's right to remain nameless.

``It sends the message, `You can have your say if it's responsible,' '' she said in a hearing in her downtown Miami chambers.

Hvide, former chief executive officer of Hvide Marine Marine, alleges that an unnamed person -- who posted under such names as ``justhefactsjack''-- made defamatory comments, calling Hvide a criminal, in AOL and Yahoo! chat rooms. He denies the charge, and Hvide doesn't have a criminal record in Florida. But his Fort Lauderdale attorney, Bruce D. Fischman, could not sue someone he could not find.

Privacy advocates said the ruling sends a frightening message to Internet users: If you critique someone online, a lawsuit may be coming your way.

``This has become an increasingly common tactic to silence criticism on the Internet,'' said David Sobel, general counsel for the Washington, D.C.-based Electronic Privacy Information Center. ``If the courts decline to provide some protection for anonymity, then that really is a negative development for free speech on the Internet.''

In recent years, people under attack from anonymous message-posters have increasingly relied on subpoenas to root out their attackers' identities. But Yahoo! rarely notified its customers when they were being sued, so the anonymous writers had no chance to challenge the subpoena. Thinking their screen names were protection enough, they were unmasked without a fight.

But under pressure from such agencies as Sobel's, Yahoo! recently changed that policy. Hvide's anonymous critic had time to hire a lawyer.

That lawyer, Christopher K. Leigh of Fort Lauderdale, contended in oral arguments that ``anonymity encourages candor and frank discussion where it wouldn't normally occur.''

Schockett countered that anonymity encourages irresponsibility.

Yahoo! attorney Clifford A. Wolff said the Internet company would not take a position one way or another on the issue -- but indicated the company wouldn't contest a judge's order.

Amid mounting financial troubles, Hvide stepped down in June 1999 after 29 years running his family's Port Everglades company. Hvide Marine, a publicly traded global marine services company with $50 million in revenues, filed for bankruptcy two months later.

Under a half-dozen screen names, the online postings started in 1998 and accused Hvide of criminal activity and running the company into the ground. Hvide's attorneys subpoenaed Yahoo! for the posters' identities. They were all traced back to one e-mail address: inquizitr1@aol.com.

``We can't do a thing about it without litigating it,'' Fischman argued before the judge. ``Let me take his deposition.''

But the American Civil Liberties Union of Florida, which urged Schockett to keep the identity secret, fears the decision could set millions of chat room users on edge about every posting they make.

``Hvide made general allegations about being criticized and being damaged, and I think the judge needs to look into those before opening the door to a policy that may threaten free speech on the Internet,'' ACLU Executive Director Howard Simon said after the hearing.

Schockett placed a 20-day stay on her ruling to allow time for an appeal, but Leigh said his client has not decided whether to appeal.

HVIDE