Lavabit in the Fourth Circuit

For those who are following the saga of Lavabit, the company has now filed its brief in the Fourth Circuit. [Brief review:  Lavabit ran an encrypted email service allegedly used for communication by Edward Snowden.  As part of its investigation, the US government sought to have Lavabit turn over the private encryption SSL key that would have decrypted Snowden's mail (and also the mail of all 400,000 other Lavabit users).  Lavabit complied but simultaneously shut down its service.]  Here's a taste of the brief:

The orders requiring Lavabit to produce its private keys were unlawful. In district court, the government relied on what can charitably be described as a mélange of theories;; at turns, the government argued that it was entitled to Lavabit’s private keys by virtue of the Pen Register Statute, the Stored Communications Act, and a grand jury subpoena. Each of those theories is completely without merit. The district court’s order of contempt should be vacated and this case remanded for further proceedings consistent with that conclusion.

Though it might not be clear to readers of this short summary, the order under the Stored Communications Act involved the application for and receipt of a search warrant by the government.  The Pen Register statute and grand jury subpoena, by contrast, were issued on lesser showings of evidentiary need.