WASHINGTON — Prosecutors investigating the disclosure of thousands of classified government documents by the anti-secrecy group WikiLeaks have gone to court to demand the Twitter account activity of several people linked to the organization, including its founder, Julian Assange, according to the group and a copy of a subpoena made public late Friday.
The subpoena is the first public evidence of a criminal investigation, announced last month by Attorney General Eric H. Holder Jr., that has been urged on by members of Congress of both parties but is fraught with legal and political difficulties for the Obama administration. It was denounced by WikiLeaks, which has so far made public only about 1 percent of the quarter-million confidential diplomatic cables in its possession but has threatened to post them all on the Web if criminal charges are brought.
Dozens of Pentagon and State Department officials have worked for months to assess the damage done to American diplomatic and military operations by the disclosures. In recent weeks, Justice Department officials have been seeking a legal rationale for charging Mr. Assange with criminal behavior, investigating whether he had actively solicited leaks and or provided technology to facilitate them.
The move to get the information from five prominent figures tied to the group was revealed late Friday, when Birgitta Jonsdottir, a former WikiLeaks activist who is also a member of Iceland’s Parliament, received an e-mail notification from Twitter.
In the message, obtained by The New York Times, the company told her it had received a legal request for details regarding her account. It supplied the names of lawyers who specialize in electronic communications, and warned that the company would have to respond to the request unless the matter was resolved or “a motion to quash the legal process has been filed.” The subpoena was attached.
The subpoena was issued by the United States attorney for the Eastern District of Virginia on Dec. 14 and asks for the complete account information of Pfc. Bradley Manning, the Army intelligence specialist awaiting a military court martial under suspicion of leaking materials to WikiLeaks, as well as Ms. Jonsdottir, Mr. Assange and two computer programmers, Rop Gonggrijp and Jacob Appelbaum. The request covers addresses, screen names, telephone numbers and credit card and bank account numbers, but does not ask for the content of private messages sent using Twitter.
Some published reports in recent weeks have suggested that the Justice Department may have secretly impaneled a grand jury in the Eastern District of Virginia, which often handles national security cases, to take evidence in the WikiLeaks inquiry. But the subpoena, unsealed by a Jan. 5 court order at the request of Twitter’s lawyers, was not issued by a grand jury.
In messages in its own Twitter feed, WikiLeaks confirmed the subpoena, and suggested that Google and Facebook might also have been issued such legal demands. Officials for Facebook declined to comment, and Google did not immediately respond to an inquiry.
WikiLeaks suggested that the United States was hypocritical for promoting an “Internet Freedom” initiative and decrying Iran’s interference with activists’ use of the Internet while pursuing a criminal investigation of the group’s activities.
Using the abbreviation for direct messages, the only messages on Twitter that are not publicly accessible for some users, WikiLeaks said, “If the Iranian govt asked for DMs of Iranian activists, State Dept. would be all over this violation of ‘Internet freedom.’ ”
Mr. Appelbaum wrote in his Twitter feed on Saturday that Twitter’s lawyers had warned him against using or receiving private messages using the service. “Do not send me Direct Messages,” he wrote. “My Twitter account contents have apparently been invited to the (presumably-Grand Jury) in Alexandria.”
Jodi Olson, a spokeswoman for Twitter, said the company would not comment on the subpoena. But she said that “to help users protect their rights, it’s our policy to notify users about law enforcement and governmental requests for their information, unless we are prevented by law from doing so.”
Of the five individuals named in the subpoena, only two — Mr. Manning and Mr. Appelbaum — are American citizens. The others include an Australian, Mr. Assange; Ms. Jonsdottir, of Iceland; and Mr. Gonggrijp, a Dutch citizen. This raised the possibility of a diplomatic quarrel between the United States and allied nations whose citizens were among those covered by the subpoena. They could argue that American laws were being used to stifle free communications between individuals who were not American citizens, and who were not in the United States at the time of the messages.
Reached by telephone in Iceland, Ms. Jonsdottir said that she would be filing an appeal. She said that she had not exchanged sensitive information using her Twitter account, “but it’s just the fact that another country would request this sort of personal information from an elected official without having any case against me.”
Iceland’s foreign minister, she said, has requested a meeting with the American ambassador to Iceland to ask, among other things, whether a grand jury inquiry prompted the subpoena.
“It is so sad,” she said. “I have so many friends in the U.S., and there are so many things that I respect about it. This is not how America wants to present itself to the world.”
Obama administration officials on Saturday indicated that the investigation was still in an early phase, with a broad net cast for evidence regarding WikiLeaks’ interactions with Private Manning, 23, who has been held for months in a military detention center at Quantico, Va., on suspicion of being WikiLeaks’ source for the classified military and diplomatic records.
The subpoena seeks Twitter account activity since Nov. 1, a few weeks before Private Manning is alleged to have started downloading documents from his military computer and giving them to WikiLeaks.
Glenn Greenwald, a lawyer and writer who posted the subpoena on his blog at Salon.com, suggested investigators may be focusing on the first of the disclosures of which Private Manning has been accused — a military video depicting two American helicopters in Iraq in 2007 firing at people on the ground who included two Reuters journalists, both of whom were killed. An edited version of the video listed Mr. Assange, Ms. Jonsdottir, and Mr. Gonggrijp as producers.
Leak prosecutions have been rare and have almost always focused on government employees who disclose classified information, not on journalists or others who publish it. In its first two years, the Obama administration has charged five current or former government employees for such leaks, a record.
But there has never been a successful prosecution of a nongovernment employee for disseminating classified information. Most legal experts believe that efforts to bring criminal charges against WikiLeaks volunteers would face numerous practical and legal obstacles, and some human rights organizations and constitutional scholars have said such a prosecution could damage press freedom.
Technology and telecommunications companies receive thousands of subpoenas and court orders every year in which government and law enforcement authorities demand a broad range of information about their customers, from the content of their e-mails, to the Internet Protocol addresses of their computers, to their files that are stored online and location data from their cellphones.
The volume of requests has become so large, and the rules guarding personal information so patchy, that in March a coalition of Internet companies and communications carriers teamed up with civil liberties groups in an effort to lobby Congress. The coalition, Digital Due Process, wants to strengthen the privacy protections for online information and simplify the laws governing access to those records by law enforcement authorities.
WikiLeaks faced severe criticism after it posted military documents from the war in Afghanistan in July without removing the names of Afghan citizens who had assisted the United States. Since then, WikiLeaks has become far more cautious, stripping names out of Iraq war documents posted online and moving slowly in publishing the 251,287 diplomatic cables it obtained six months ago.
As of Saturday morning, the group had published 2,017 State Department cables on its Web site.
But Mr. Assange has posted an encrypted “insurance” file on several Web sites containing all or most of the unpublished cables and possibly other classified documents. Thousands of supporters around the world have downloaded the file, and Mr. Assange has suggested that if legal action is taken against him or the organization, he would release the encryption key and make the documents public.
“If something happens to us, the key parts will be released automatically,” Mr. Assange said in an online interview with readers of The Guardian last month.
Scott Shane reported from Washington, and John F. Burns from London. Reporting was contributed by Ravi Somaiya from London, Claire Cain Miller and Miguel Helft from San Francisco, Eric Lipton from Washington, and J. David Goodman from New York.