>Perhaps this is a dumb question: How does that solve the problem? Either its readable by all or by none.

There's a service called TelFriends that brokers keys between you and your friends.

Ordinary people don't have to care about that - typically their username/password is used in whatever app they're using to transparently decrypt records on the fly.

And since we're talking about privacy, you own your domain and its data - not Telnic, Google, or Facebook.