What you are suggesting is similar to a "blacklist" that may or may not be "fair" to bidders.

Personally, I would be interested to see them, but might not automatically put them on my blocked bidder list...mostly because I tend to give folks the benefit of the doubt, and/or work through ebay/paypal channels to take care of deadbeats or whatever.

I have to say it would be nice to know up front if someone bidding on one of my auctions has been trouble for someone in the past, but I probably could also tell that from thier feedback.

This is an interesting question, but sometimes I put people on my blocked bidder list just because I got a "bad vibe" during an auction, or because they seemed like troublemakers (for example, I had one guy complain that I listed a car part as "perfect" and it arrived to him with a mark on it from another plastic part, but it came off with simple rubbing. No negative feedback was left, but it was just enough hassle via emails before we agreed it was, essentially, in "perfect" condition. It was just enough hassle for me that I just made the choice to not deal with him in the future. It seemed like he was just trying to "bully" me into a partial refund.

However, as much as I dislike the guy and will not to business with him again, I would not want to prevent him from doing business with others on the board because it just might have been a bad day for him, and after all, things were resolved well enough.

That kind of stuff would prevent me from being comfortable putting people like him on what would, by and large, be the reputable collecting hobby as a whole.