@evan The answer is go back to LiveJournal and Alice gets to decide. If her post is fully public, anyone can comment on it. If it's private and Bob is in a group of people she shared it with, only Bob and the people in that group can see the post and comment. Now if Bob wants to make a copy of her post and share it privately this his group of friends, that's his business but then he's probably not a very good friend.
O
obscurestar@mastodon.social
@obscurestar@mastodon.social