I'd feel happier not trusting the server at all but I still want a place to have a copy of my code and for collaboration.
So I created Ghostfork. The client is all open source. It acts like a helper for git, being a middle man for all communication with the server. The ghostfork server is your new remote. Everything is encrypted before going out, and decrypted when coming back. I want to assume the server operator is not only not trustworthy -- they might even be incompetent.