I also thought about RSS as a basis for social media (I call it 'Really Social Sites'), but I think trying to make certain stuff private is against the whole id

I also thought about RSS as a basis for social media (I call it 'Really Social Sites'), but I think trying to make certain stuff private is against the whole idea of pub/sub and therefor RSS. I'm not saying you're wrong though, I just think mixing private and public (that's where the word 'publish' is coming from, right?) makes it more confusing. I do think there's a gap to fill in RSS based social media, because users of current social media would like to send a private message (or at least not public) from time to time. I basically cover this with a contact form and email, at the moment. Sounds crude and not very techy, but it works like a charm.