Another way of maintaining order is by making ignoring a 2-way street. What I mean is this: If user 1 ignores user 2, then user 2 also stops recieving posts from user 1. This way you sort of take away the users right to read your posts (at least directly) and makes Hubski less functional as a punishment for being ignored. User 2 is then less likely to get into the discussion, because it takes a lot more effort to find the post. I don't know if this is a good idea, since it still has some problems. But it is what people do. They don't start to talk to people they don't want a discussion with in the first place, unless the other person talks to them. Anyway, my two cents.
If we were to enable blocking of specific users from commenting on your posts, I think we would also need to make the list of users that you block public. Also, I think the block would only function on your own posts, and not on replies to your comments on other’s posts. The question IMHO, is whether what is gained from this is worth what is lost. Trolling will be greatly diminished, which would be a boon; however, I wonder if people will avoid users that ban too liberally, which would be an important counter to abusive blocking. I like that the system puts power in the hands of hubskiers, but I wonder to what extent the community would allow it to be abused. Importantly, I don’t think a poster should be able to delete another’s comments. The most they could do is prevent future ones.
One other thought: although you might not see the ignored comment, everyone else does, and therefore it can still disrupt the conversation.