There has been some talk of privacy and gnusocial. It's worth thinking about, but I'm inclined to be cautious about trying to retrofit security to it. I think that would be likely to end badly and give users a false sense of security. It's better to say that gnusocial and related systems are fully public and unless the OStatus protocol changes are likely to remain so. Anyone, including all of the spy agencies of all of the nation states, can read what you write here.