Lavabit's encrypted storage was a paid feature that was used by less than 10% of users. From the wording, it sounds like he never stored passwords for those accounts. It's possible that Snowden was the first premium customer for which Lavabit was issued a warrant.
> Levison isn’t an privacy absolutist. He has cooperated in the past with government investigations. He says he’s received “two dozen” requests over the last ten years, and in cases where he had information, he would turn over what he had.
> “I’m not trying to protect people from law enforcement,” he said. “If information is unencrypted and law enforcement has a court order, I hand it over.”
http://www.forbes.com/sites/kashmirhill/2013/08/09/lavabits-...