MIAMI, May 26 (UPI) -- An anonymous computer user whose identity was ordered revealed by a Miami judge is trying to decide Friday whether to appeal the decision.

The message writer was accused of using Yahoo! and America Online chat rooms to unjustly accuse the former owner of a bankrupt marine supply company of criminal behavior.

Miami-Dade County Circuit Judge Eleanor Schockett ordered the firms to reveal the message writer's name, but sealed the order for 20 days to give him time to appeal. His attorney said the decision on whether to appeal has not yet been made.

Court observers said it could be the first court order questioning whether participants in chat rooms and other internet communication has a constitutional right to remain anonymous.

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

Christopher K. Leigh, the attorney for the unidentified defendant, said, anonymity "encourages candor and frank discussion where it wouldn't normally occur."

Howard Simon of the Florida American Civil Liberties Union cautioned the ruling Thursday would affect millions of chat room users and could "threaten free speech on the Internet."

Yahoo! attorney Clifford K. Wolff said the firm would not take a position on the issue.

J. Erik Hvide, former head of Hvide Marine, filed the suit seeking the identity of the writer.

He said the writer used such on-line monikers as "justthefactsjack" to call Hvide a criminal in chat rooms on AOL and Yahoo! His attorney, Bruce D. Fischman, said Hvide couldn't sue someone he couldn't find.

Hvide stepped down as head of the global marine supply business that does $50 billion in revenues a year in June 1999. The company filed for bankruptcy two months later but continues to do business.