Lavabit, the secure email company that shut down in 2013 rather than hand over its encryption key to the U.S. government, has joined the growing list of companies filing amicus briefs on Apple’s behalf as it battles the FBI in court, TechCrunch reports. In the brief, Lavabit details the “extraordinary assistance” the FBI demanded three years ago, after public disclosures by NSA whistleblower Edward Snowden led authorities to the…