[tizrsxko] Censorship by friends, or social networking through censorship

It seems straightforward to create a social network system like Facebook based on censorship carried out by friends.

A person makes a post, visible to friends.  One of the friends dislikes it so pushes the "Censor this" button which deletes the post.  Any friend can do this.  Then, the original poster is notified of who censored the post, and given an opportunity to un-friend, or create a friend group to make future posts not seen by that censor.  Typical friend groups in this context will be defined as exclusion, "all friends except some list", though inclusion groups are possible, too.

Censorship is transparent: you see who opposes your speech.  People will form communities of speech that they agree with, or at least tolerate.  (Tricky problem: what you can tolerate changes day-to-day; should people interact with you based on how you acted on your worst day?  We probably need something client-side -- something that understands your stress level that day -- that also limits what you see that day in your best interest.)

Should the metadata of who is and who is not able to see a post be visible with the post to those who can see it?  Maybe a rabbit hole of visibility of the metadata.

Public posts are trickier.  Several ideas: It's not possible to follow someone's feed of public posts without being their friend: public posts are indexed by cryptographic hash, so you definitely have to make an effort to go find a post (get a friend to snitch) to find the public URL of a public post.  Each public URL is unique to the friend who sees it, so knowing the leaked URL is enough for the original poster to identify who snitched and then un-friend or make limited.  (Public posts can still be limited about who is notified of its existence.)  Posts have watermarking that can similarly identify from screenshots.  Provide a utility with which anyone can easily forge a post from anybody with any content, for plausible deniability.

Comments on posts are also tricky.  A nice feature would be, if a post with comments is censored but the poster reposts to a more limited friend group, the old comments get migrated.

Previously on the theme of Anyone Can Censor.