PGP - one can store the keys on one's own server. In Virturo, it appears it has to be on Virutro servers. So hypothetically, we could have a Lavabit moment.
I think it's been iterated before, but in the future we intend to open source our key serving software. There's still much work to be done on that front. We love PGP's crypto, but we found a few problems with it in general:
1) It's hard for the normal person. (The user experience for PGP is just horrendous)
2) Before you send an email to someone you have to know their public key.
With that said, we have done some research on integrating PGP like public key encryption along with our current key serving mechanism. With public key, using Virtru will be essentially equivalent to holding the keys yourself. Look for more of this in the future :-)
See my other comment about Virtru and allowing for self-hosted keys. We also don't host the content, so different laws apply..I think znelson commented on that somewhere in the thread already.
1) It's hard for the normal person. (The user experience for PGP is just horrendous)
2) Before you send an email to someone you have to know their public key.
With that said, we have done some research on integrating PGP like public key encryption along with our current key serving mechanism. With public key, using Virtru will be essentially equivalent to holding the keys yourself. Look for more of this in the future :-)