Thanks very much, and I do agree. I do fear though, that open door communities are inevitably prone to abuse, we've seen it in so many online forums etc. I wonder how long it will be before Hubski starts to attract that kind of attention? Matt at Metafilter had to impose a $5 'sign up' fee just to stop the trolls having a field day. It's a sad fact of life methinks.
I think one advantage Hubski has over other sites is that users have complete control over what you see and don't see. You can ignore and follow users, domains, and tags to customize Hubski to be exactly what you want it to be. There is also the mute function which you can read about more here. About a year ago we had a very large influx of users, some of who were troll-y and circlejerky. Their existence was barely noticed by the majority of existing Hubski users. They were quickly ignored, got bored and left. Trolls can't troll if no one pays attention to them. While I don't think there is any perfect solution to the issue of online commenters and trolling I do believe that Hubski has been set up in a way that takes a lot of power away from the trolls and gives that power to the users.