As his family business slid toward bankruptcy, J. Erik Hvide became the subject of endless taunts from nameless stockholders venting their frustrations on Internet chat rooms.

Since being ousted from his office at Hvide Marine Inc. in Fort Lauderdale, the Delray Beach man has struck back with a lawsuit that seeks to unmask his attackers -- and potentially redefine what anonymity means on the World Wide Web.

On Thursday, a Miami-Dade judge said America Online and Yahoo!, two of the most popular service providers on the Internet, must release the names of their customers who lambasted Hvide and his company in electronic chatter. The ruling was made over the objections of the American Civil Liberties Union, which argued that the use of "screen names" by people in chat rooms encourages free speech, allowing them to express unpopular views without inhibition.

Hvide's lawyer, Bruce Fischman of Fort Lauderdale, said that cloak of secrecy also allows people to make false or defamatory statements. Hvide's critics, using pseudonyms such as "justhefactsjack," and "inquizitr1," suggested that Hvide profited while the publicly traded company tumbled in value, and the company was the subject of a securities investigation.

Fischman said the Internet postings continued even after Hvide left the company last year. "We received phone calls from shareholders who said they feel the postings and his termination caused the stock to take a dive," he said.

Lawsuits against the Web's "John Does" are not uncommon; Fischman's law firm, Fischman Harvey & Dutton, has filed several. Usually they target companies like Yahoo!, forcing them to give up the identities of their vocal customers, who then get sued themselves.

This time, a Doe -- rather, "justhefactsjack" -- tried a preemptive strike. He hired his own lawyer, Christopher Leigh, who argued that his identity should be kept secret until the judge determines whether the chat-room statements amount to defamation.

But Judge Eleanor Schockett said those who bad-mouth corporate executives in chat rooms where they agonize over stock prices don't have the same protection as political activists who must stay anonymous for fear of reprisal. Her ruling may be the first in to address protection of chat-room identities.

Regardless, Leigh said his client's comments were not defamatory; his client has yet to decide whether to appeal the ruling.