The US Department of Justice served Twitter with a subpoena seeking information about the accounts of the Wikileaks organization, its founder Julian Assange and other members and supporters, according to Twitter posts from people involved and documents published by Salon.com.
The DOJ sent Twitter the subpoena on December 14, but it remained sealed until January 5 when a judge granted Twitter's request that it be allowed to notify the users whose records had been requested, according to copies of the documents posted by Salon.com late on Friday night.
The DOJ wants information dating back to November 1, 2009, about Twitter user names, messages, physical and email addresses, Twitter session times, IP addresses and credit card and bank account information.
Wikileaks is a nonprofit organisation that publishes classified, confidential documents, often from government agencies. The DOJ probe likely focuses on Wikileaks' release in November of hundreds of thousands of secret diplomatic cables from the US State Department.
The situation has alarmed and embarrassed the US government, which has condemned Wikileaks, saying the release of the documents endangers the country's national security and the safety of soldiers and US government workers. It wasn't clear Saturday if Twitter had turned over the information.
In addition to Assange, the DOJ is also seeking information from the accounts of Icelandic parliamentarian Birgitta Jonsdottir and US soldier Bradley Manning, who is suspected of having assisted Wikileaks with obtaining classified documents and is now in jail awaiting a court martial proceeding.
Separately on Saturday, Assange and Jonsdottir criticised the DOJ, saying the agency shouldn't be forcing Twitter to turn over information.
Speaking to Agence France Presse (AFP), Jonsdottir said Iceland's justice minister is looking into the issue at her request. "I am speaking to US lawyers... because I want to try to stop that Twitter needs to hand over this information," she told AFP.
Neither the DOJ nor Twitter responded to requests for comment.