Lavabit also sent the private keys from their servers to clients using TLS that utilized RSA for key exchange. Levison was to put it into a word, a fool, for letting that happen. Once he had to submit the private RSA-key for the certificate, FBI could decrypt every past session, and every private key of every user. IMO he'd have to put a hell of a lot of effort if I'm ever going to look at his creations again.