EFF urged the Fourth Circuit Court of Appeals in an amicus brief to rule an email provider could not be forced to disclose its private encryption key to the government.
In July, the Department of Justice demanded Lavabit's private key—first with a subpoena, then with a search warrant. Although the government was investigating a single user, having access to the private key means the government would have the power to read all of Lavabit's customers' communications. After Lavabit resisted complying with the demand, it was held in contempt of court and fined $5,000 a day until it turned the key over. Since Lavabit's business model is founded in protecting privacy, after turning the key to the government, Lavabit shut down its service, feeling it could no longer guarantee security to its customers.
Our amicus brief argues Lavabit should not have been held in contempt because the request for the private encryption key was unreasonable under the Fourth Amendment, would put the private communications and data of Lavabit's 400,000 customers at risk of exposure to the government and destroy the integrity of encryption over the Internet.
In April 2014, the Fourth Circuit rejected Lavabit's appeal, ruling Lavabit had waived his legal arguments by not raising them in the lower court. The Fourth Circuit did not decide conclusively whether or how the government can compel an email provide to disclose its private encryption keys to the government.