Backed by a magistrate judge's court order from Dec. 14, the newly disclosed documents sent to Twitter Inc. by the U.S. attorney's office in Alexandria, Va., demand details about the accounts of WikiLeaks founder Julian Assange and Pfc. Bradley Manning, the Army intelligence analyst who's in custody and suspected of supplying WikiLeaks with classified information.
The others whose Twitter accounts are targeted in the prosecutors' demand are Birgitta Jonsdottir, an Icelandic parliamentarian and one-time WikiLeaks collaborator; Dutch hacker Rop Gonggrijp; and U.S. programmer Jacob Appelbaum. Gonggrijp and Appelbaum have worked with WikiLeaks in the past.
Justice Department Matt Miller declined comment on the disclosure in the case, which intensified following WikiLeaks' latest round of revelations with the posting of classified State Department diplomatic cables. The next day, Nov. 29, Attorney General Eric Holder vowed that anyone found to have violated U.S. law in the leaks would be prosecuted.
Assange said the U.S. move amounted to harassment, and he pledged to fight it.
"If the Iranian government was to attempt to coercively obtain this information from journalists and activists of foreign nations, human rights groups around the world would speak out," he told The Associated Press in an e-mail.
The demand by prosecutors sought information dating to Nov. 1, 2009, several months before an earlier WikiLeaks release.
Manning is in a maximum-security military brig at Quantico, Va., charged with leaking video of a 2007 U.S. Apache helicopter attack in Baghdad that killed a Reuters news photographer and his driver. WikiLeaks posted the video on its website in April of last year.
In a statement about the demand to Twitter for information, WikiLeaks said it has reason to believe Facebook and Google, among other organizations, have received similar court orders. WikiLeaks called on them to unseal any subpoenas they have received.
The subpoena from the U.S. District Court for the Eastern District of Virginia ordered Twitter to hand over private messages, billing information, telephone numbers, connection records and other information about accounts run by Assange and the others.
A copy of the subpoena, sent to the AP by Jonsdottir, said the information sought was "relevant to an ongoing criminal investigation" and ordered Twitter not to disclose its existence to any of the targets.
But a second document, dated Jan. 5, unsealed the court order. Although the reason wasn't made explicit in the document, WikiLeaks said it had been unsealed "thanks to legal action by Twitter."
Twitter declined comment on the matter, saying only that its policy is to notify its users, where possible, of government requests for information.
Neither Facebook Inc. nor Google Inc. immediately returned messages Saturday.
The Obama administration volunteered little new information about its criminal investigation against Assange and WikiLeaks after news of its subpoena leaked. Under rules governing grand jury investigations _ in which U.S. prosecutors present evidence and testimony to selected private citizens behind closed doors to seek their approval to formally file charges _ government lawyers are not allowed to discuss the case until charges are announced publicly.
It was not immediately clear how the data being requested would be useful to investigators. Twitter's logs could reveal the Internet addresses that Assange and WikiLeaks supporters have used, which could help track their locations as they traveled around the world. The information also might identify others with official access to WikiLeaks' account on Twitter who so far have escaped scrutiny.
Assange's lawyer, Mark Stephens, said targeting Twitter showed how desperate U.S. officials were to pin a crime on the WikiLeaks founder.
Stephens told the BBC it was an attempt to "shake the electronic tree in the hope some kind of criminal charge drops out the bottom of it."
Jonsdottir said in a Twitter message that she had "no intention to hand my information over willingly." Appelbaum, whose Twitter feed suggested he was traveling in Iceland, said he was apprehensive about returning to the U.S.
"Time to try to enjoy the last of my vacation, I suppose," he tweeted.
Gonggrijp praised Twitter for notifying him.
"It appears that Twitter, as a matter of policy, does the right thing in wanting to inform their users when one of these comes in," Gonggrijp said. "Heaven knows how many places have received similar subpoenas and just quietly submitted all they had on me."
The news of the subpoena follows months of angry back and forth between U.S. officials and WikiLeaks, which has released reams of secret U.S. military documents on the wars in Iraq and Afghanistan and more recently, thousands of classified U.S. diplomatic cables.
U.S. officials say posting the military documents put informers' lives at risk, and that revealing diplomatic cables has made other countries reluctant to deal with American officials.
WikiLeaks denies that its postings put any lives at risk and says Washington merely is acting out of embarrassment over the revelations contained in the cables.
WikiLeaks and its tech-savvy staff have relied on American Internet and finance companies to raise funds, disseminate material and get their message out.
WikiLeaks' frequently updated Facebook page, for example, counts 1.5 million fans and its Twitter account has a following of more than 600,000. Until recently, the group raised donations via U.S. companies PayPal Inc., MasterCard Inc., and Visa Inc., and hosted material on Amazon.com's servers.
But the group's use of American companies has come under increasing pressure as it continues to reveal U.S. secrets. PayPal and the credit card companies severed their links with site and Amazon.com booted WikiLeaks from its servers last month.
The actions sparked a cyberfight with WikiLeaks sympathizers, who attacked the company's sites for days.
Assange is currently out on bail in Britain, where he is fighting extradition to Sweden on sex crimes allegations. His next hearing is scheduled for Tuesday.