Michael Phillips wrote in The New Yorker about How the Government Killed a Secure E-mail Company
"Which secret surveillance scheme is involved in the Lavabit case? The company may have received a national-security letter, which is a demand issued by a federal agency (typically the F.B.I.) that the recipient turn over data about other individuals. These letters often forbid recipients from discussing it with anyone. Another possibility is that the Foreign Intelligence Surveillance Court may have issued a warrant ordering Lavabit to participate in ongoing e-mail surveillance. We can’t be completely sure: as Judge Reggie Walton, the presiding judge of the FISA court, explained to Senator Patrick Leahy in a letter dated July 29th, FISA proceedings, decisions, and legal rationales are typically secret. America’s surveillance programs are secret, as are the court proceedings that enable them and the legal rationales that justify them; informed dissents, like those by Levison or Senator Ron Wyden, must be kept secret. The reasons for all this secrecy are also secret. That some of the secrets are out has not deterred the Obama Administration from prosecuting leakers under the Espionage Act for disclosure of classified information. Call it meta-secrecy."
I really think the secrecy part is crazy.