It is not unreasonable to have closed communities. On a decentralized system like steem, it would require cryptography, and encryption, to make it work.
My ideal network would allow closed communities with members therein voting full weight and receiving rewards proportional to those weight, if it were a reward system.
My ideal directly contradicts the current steem model of "everyone in everyone else's business", but this aspect of steem is what has driven me and others largely away. I have divested about 80% of my holdings and am contemplating divesting the rest.
One way to change my mind would be to have cryptographically closed communites, and less nosiness, trolling, and harassment, but I'm not holding my breath.
Finally, the FUD about people doing "illegal" things with cryptography is shameful, although I know you don't mean it as FUD.
The ability to communicate freely is enshrined in the charters of many societies, and an online society should be no different. A more important worry is what horrors a government will inflict on its people. I welcome any technology that impedes governmental oppression. For those thinking that governments will not commit atrocities, you need to turn off Dancing with the Stars and start paying attention to world events.
RE: An Idea for Password Protected and Censorship Resistant Posts/Message Passing