@Dazinism Interesting... ActivityPub would likely not allow actually deleting other people's comments once they've federated, but there's some things could do along these lines:

• Delete your instance's copy of a comment in a thread you started, so that people who read the canonical thread will not see that comment.
• Block someone from participating in a thread so their comments will only spread to the followers of the commenter (and other users of their instance) but won't be accepted by your instance and won't be forwarded to your followers.
• Lock a thread you started so that any further replies will be treated the same as in the previous point.

Most of this should be pretty easy to implement using existing functionality such as boundaries, and would be usuful both for thread starters and Topic curators. But anything we can do with those will be limited compared to we'll be able to do when implementing proper Groups.