I don't like the ability for users to block commenters from their posts, thinking on it. I think a lot of the value from Hubski occurs from the conversations that users have in the comment section of various threads, among themselves, whether or not the author of the thread participates. I'm not really for letting the author ban people from participating.

On the other hand, I get the concern of regulating trolls and spammers. Unfortunately, I think humans being humans, they will not use a ban option for those purposes, and will ban people they merely disagree with, or whose tone they do not like. It's like the Reddit down vote. It was never supposed to mean 'click if you disagree with the comment above you' but that is EXACTLY what it means in reality.

Moderation is a tough nut to crack, but I'd sooner be in favor of posts authors having the ability to demote posters to the bottom than outright ban, but even this is really just a ban of sorts.

What about letting the author flag a post making the poster/post appear in another color (or otherwise mark it), with the ability to place a text message in a tool-tip so that if you hover over it users get to see why the author flagged it. This tool tip or text-flag could contain a 'agree/disagree' option, basically inviting users to vote. If enough disagree, nothing much happens, but if enough agree, the post gets demoted to the bottom or even banned or otherwise sanctioned.

This way, there are no down votes for Hubski per se, but rather the ability for the author to 'turn on' down votes with an explanation for very specific posts.

I've not heard of this before, but it is an interesting idea to me.