Twitter’s lawyers are trying to block US authorities from accessing personal data as part of a WikiLeaks investigation. Wikileaks briefs asked a US judge to overturn a ruling from earlier this month, forcing Twitter to hand over account details to the US Department of Justice.

The government wants access to Twitter account details for three users who had contact with Wikileaks including American computer security researcher Jacob Appelbaum, Birgitta Jonsdottir, a member of the Icelandic parliament, and Rop Gonggrijp, a Dutch computer programmer. Twitter has been told to give account information such as mailing addresses and session logs to the government.

However Twitter said the request violates US federal law, threatens the clients’ right to privacy and intrudes upon their freedom of association. The three are supported by the Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU).

The ACLU and the EFF argue that the order would require Twitter to divulge all direct messages, even those unrelated to WikiLeaks. It “has a chilling effect not only on the parties’ speech and association rights, but on the rights of Twitter users in general,” the organisations said in a joint statement.

Judge Theresa Buchanan earlier rejected arguments that the disclosure invades privacy, saying that the users had already made their user information public via Twitter.