The users in question are American security researcher Jacob Appelbaum, Icelandic politician Birgitta Jonsdottir and Dutch computer programmer Rop Gonggrijp. They are believed to be (or have been) in contact with WikiLeaks, and the US government is trying to find out details about their possible involvement with the release of the US diplomatic cables, Wikileaks founder Julian Assange and/or Bradley Manning, the military analyst that has allegedly shared the cables with WikiLeaks.
According to eWeek, the information that the government is after are the mailing addresses associated with the Twitter accounts in question and session logs.
The Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU) have also challenged the ruling on behalf of Birgitta Jonsdottir, and claim that "the secret government demands for information about the subscribers' communications came to light only because Twitter took steps to ensure its customers were notified and had the opportunity to respond."
"Except in very rare circumstances, the government should not be permitted to obtain information about individuals' private Internet communications in secret. This is not one of those circumstances," said Aden Fine, staff attorney with the ACLU Speech, Privacy and Technology Project. "If the ruling is allowed to stand, our client might never know how many other companies have been ordered to turn over information about her, and she may never be able to challenge the invasive requests."
"Services like Twitter have information that can be used to track us and link our communications across multiple services including Facebook and Gmail," said EFF Legal Director Cindy Cohn. "The Magistrate's ruling that users have no ability to protect that information from the U.S. government is especially troubling."
Cohn pointed out the broader implications of the court's decision earlier this month: “With so much of our digital private information being held by third parties – whether in the cloud or on social networking sites like Twitter – the government can track your every move and statement without you ever having a chance to protect yourself.”
The lawyers argue that the decision violates the defendants' First (freedom of speech and association) and Fourth (privacy) Amendment rights and that they should also be granted a motion to unseal all remaining unsealed documents regarding the Twitter Order and any similar orders to entities other than Twitter.