@evan What do current implementations do?

By default, if you're replying in a followers-only thread, it should be visible to the same people as what you're replying to. That would usually mean cascading up to the OP. If Bob replies to Alice, then Carol replies to Bob, then all three posts should be visible to all Alice's followers and only Alice's followers.

Bob should have other options - the standard "public", "Bob's followers", and "mentions only" - but it should always be a conscious choice to deviate from the default. If technically possible, allowing the intersection and the union of Alice and Bob's followers would be great additional options. There are plenty of cases where either widening or narrowing the audience for a reply might be appropriate. If Bob does choose something other than default, that would be the new default for Carol's reply to Bob.

I imagine unions and intersections could get very messy in a long thread with multiple people changing the visibility level at different stages; I'm not sure if that poses a real technical problem? Eg Bob replies to (Alice's ∩ Bob's), then Carol replies to ((Alice's ∩ Bob's) ∪ Carol's), and so forth.

Giving the OP the option to restrict replies would be a nice bonus; they could control whether or not changing the visibility in replies is possible.

The current default of "show to Bob's followers" is pretty much the least likely to be what people actually want, and is by far my biggest problem with Fedi.

@evan @maj That’s what the state is today, but you asked what the visibility *should be*.

It seems that replies to a followers-only post *should be* visible to anybody who can see the original post.

@bob_zim @maj I agree!

This is a huge thread!

@evan it’s a good one, fb vs twitter style replies.