The FBI first seized archives from the encrypted Tormail service back in August, as part of the Freedom Hosting bust, but new evidence uncovered by Wired suggests those archives are now being used in completely unrelated investigations. Because Tormail was a client of Freedom Hosting, the FBI has access to all the data stored by the service, including metadata and the contents of each email. And now, there's proof they're using it.
The evidence comes from a group of credit card counterfeiters arrested last week, which used a Tormail address to accept orders. Once FBI agents discovered the address, they got a search warrant for the account's contents and then simply looked it up in the archives stored on Freedom Hosting's servers. Without that cache of data, agents would have had to compel Tormail to give up the data, which would have required an extensive legal process and potentially resulted in a Lavabit-style shutdown. Since the servers had already been seized, it was as simple as plugging in. There's still no indication that any data was ever accessed without a search warrant, but the ease with which the data was accessed is still troubling to anyone counting on encryption services to keep their email out of the hands of law enforcement.