Diaspora/Diaspora

I have a question here. is it the users that "already interacted with the post" (here I understand that as commented/liked/reshared it) or the users whom the post is available(they have access to it)?

The former, since the latter would be an information leak that's bad for the author (all members of it can figure out what the author considers one peer group/aspect) and for the other recipients (all recipients can start mapping FOAF graphs).