I was speculating earlier that maybe the whole circle/sharing confusion boils down to conflation of privacy (restricting access) and noise management (not spamming people). Without actually knowing any of the user data, I think I have an idea how I might like things to work.
The basic principle is to avoid us having to reason about propagation, or implications of things. So..
1. Distinction between private and public. If you share with Everyone, it's public. If you share with a circle(s), or individuals, it's private by default.
2. If you share with a circle, you can tick a Allow Reshare box to make the posting public (but notice here that you still do noise mgmt, eg, you only share with your knitting circle, but you dont actually care if people outside that circle see it)
3. IMPORTANT: private/public must be hard boundaries. No complex reasoning, no transitive closures, just black and white, the ideal being something one can understand when drunk: private means no resharing. Full Stop.
3b. This means we can kill that silly admonition to be careful when resharing something Limited — “remember to be thoughtful about who you share it with”. Every time I see that, I just go “huh?” and figure I'm too dumb to work out what's kosher, so I don't bother
4. Private shares are visually distinct, eg a grey background. A smart visual designer will hopefully know how to make private shares feel obviously private in appearance
5. It is possible to toggle between private/public at any time (you can change your mind); hence also importance of the distinction being visually obvious
Does it makes sense? Am aiming for Actually Understandable more than Makes Geeks Feel Clever...