"First, why would you trust anyone else to encrypt your off-site backups for you? "
Me? I wouldn't of course, but I .can see it being a service in demand. ANd he may be using something like Silent Circle's implementation for the client; which would work if he open-sourced the software and open sourcing was mentioned. I'm only guessing from the tweets what the service might be anyway...could be totally wrong. He could also be selling peer-to-peer nodes and decentralising things (and therefore offloading liability) but I don't know how you'd monetise that (unless you charged for the software; but open source was mentioned).
I did have a whom in the draft there for a little while, but decided it was entirely too pretentious for that time in the morning. I've always thought of whoms as largely optional (unless you're talking about bells tolling).