Edward Snowden
Edward Snowden says Isis's ‘spooky fake crypto’ is a misleading scare tactic Getty Images

Federal authorities in the US have accidentally revealed a cache of case documents related to the Lavabit case that shows the encrypted web mail service was forced to shut down in order to allow the government to spy on Edward Snowden's email. The documents were posted on 4 March to the federal court system as part of Lavabit owner Ladar Levison's long battle for transparency in the case that ruined his business.

The document, which was spotted by The Wired, clearly shows Snowden's email address — Ed_Snowden@lavabit.com being the target of the 2013 investigation. Until now, there had only been speculative reports and no hard evidence against the federal authorities to show that they specifically used the platform to target Snowden.

On June 28 2013, shortly after newspapers had published the first NSA leaks from Snowden, FBI agents had approached Levison at his residence requiring him to give access to the email activity of one particular customer's account. Levison had been forbidden under threat of contempt from identifying whose e-mails the government wanted access to. Ultimately, Lavabit had to suspend its operations on 8 August after the incident as the government had ordered it to turn over its Secure Sockets Layer (SSL) private keys.

Levison has since then continued to fight to get more of the documents unsealed including using money raised by supporters back in 2013 to fund the fight for transparency. The latest revelation may provide Levison the leverage he needed to make his case stronger in front of legal authorities.

The developments of the case come at a time when US tech giant Apple is also fighting a privacy-related battle with federal authorities over refusing to unlock an iPhone, which is a crucial evidence in the San Bernardino terrorism case. The iPhone maker, like Levison, believes that back-door access to one device will pave the way to access a huge customer base data on the rest of the phones, compromising people's privacy.