(02-29) 17:35 PST SAN FRANCISCO -- A federal judge in San Francisco who had ordered the shutdown of a whistle-blowers' Web site where private bank documents were posted changed his mind Friday, conceding his original ruling might not have been constitutional.

U.S. District Judge Jeffrey White drew nationwide attention, and widespread criticism from civil liberties groups and news organizations, with his Feb. 15 injunction requiring a Bay Area Internet registrar to disable the Wikileaks.org site and prevent the organization from transferring to another server.

Wikileaks describes itself as an enabler of "principled leaking" by government and corporate insiders, who post documents on the site anonymously. The injunction was requested by a Swiss bank, Julius Baer & Co., whose documents, purporting to show tax fraud and money-laundering by customers with funds in the Cayman Islands, were displayed on the Web site.

The bank said the documents were stolen or forged and invaded its customers' privacy.

The shutdown order was negotiated by the bank and Dynadot, the San Mateo company that registered Wikileaks' use of the Web site. But the American Civil Liberties Union, Public Citizen and a host of media advocates and owners - including Hearst Corp., which owns The Chronicle - called the injunction an unprecedented assault on free expression and likened it to closing a newspaper because of objections to one article.

After a three-hour hearing Friday, White dissolved the injunction. He also rejected the bank's request to extend a restraining order that required Wikileaks and the Internet registrar to remove the bank documents from the Web site. The restraining order expired Friday.

Such decrees raise "serious questions of prior restraint (on speech) and possible violations of the First Amendment," White said.

He also said federal courts may lack jurisdiction over the case because the bank has failed to show that Wikileaks, or anyone responsible for its operations, is based in the United States.

Even if other legal obstacles disappeared, White added, any injunction against Internet posting is likely to be ineffective because the documents are "fully out in the public domain" and can be transferred to other sites.

The judge kept the bank's suit alive, but advised its lawyers to "consider whether there may be other ways to achieve the same goals," such as suing for damages. The attorneys indicated afterward that they would be willing to refile the suit in a state court if White concluded federal courts have no jurisdiction.

White's ruling Friday implied a judicial "abdication of authority over the Internet," said William Briggs, a lawyer for Julius Baer. "That means it's a frontier that's wide open."

Ann Brick, an American Civil Liberties Union lawyer, said White "understood the limits the First Amendment places on what courts can do to deprive the public of the right to know." Steven Mayer, another lawyer for civil-liberties groups, predicted the bank would encounter the same free-speech problems in state court.

White made it clear he was aware of the unflattering media coverage of his earlier ruling, and reflected on the difficulties courts face in applying established legal doctrines to the Internet and to entities like Wikileaks.

The organization says it was founded in 2006 by dissidents, journalists and others from several nations. It has a Web server in Sweden but no established headquarters and no president or formal leadership structure, only an advisory board, according to its Web site.

Like the better-known Wikipedia, with which it is not formally affiliated, it invites posters to submit, revise and comment on documents on its site, and disclaims responsibility for the contents.

Despite White's Feb. 15 injunction, Wikileaks remained accessible through its Internet Protocol or IP address, 88.80.13.160, and through so-called mirror sites in Europe that replicate its contents.

On Friday, the owner of the Wikileaks.org domain name, John Shipman, was represented in court by attorney Roger Myers. White told Myers he considered Shipman to be Wikileaks' legal representative and asked if he would object to an order that allowed the organization to regain its domain name if it removed all information that identified individual bank customers.

Myers replied that Shipman, an Australian citizen living in Kenya, has no control over the Web site. Paul Levy, an attorney with Public Citizen, said he doesn't believe a loose network of activists like Wikileaks is even susceptible to a lawsuit.

As he announced his ruling, White observed that he was encountering "a definite disconnect between the evolution of our constitutional jurisprudence and modern technology."

E-mail Bob Egelko at begelko (at) sfchronicle.com.