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. Once FBI agents discovered the address, they got a search warrant for the accounts contents and then simply looked it up in the archives stored on Freedom Hostings servers.