In the summer of 2013, secure e-mail service Lavabit was ordered by a federal judge to provide real-time e-mail monitoring of one of its users. Rather than comply with the order, Levison shut down his entire company. He said what the government was seeking would have endangered the privacy of all of his 410,000 users.

Later, he did provide the private key as a lengthy printout in tiny type.

In court papers related to the Lavabit controversy, the target of the investigation was redacted, but it was widely assumed to be Edward Snowden. He was known to have used the service, and the charges against the target were espionage and theft of government property, the same charges Snowden faced.

Now, what was widely assumed has been confirmed. In documents posted to the federal PACER database this month, the government accidentally left his e-mail, "Ed_snowden@lavabit.com," unredacted for all to see. The error was noted by the website Cryptome earlier this week, and Wired covered it yesterday.