Since the thread below got closed...could we incorporate a rating system for trades? There could be "business rules" set to determine how &when one user could "rate" another user, to prevent the misuse of it. (Somebody giving another all +1 or all -1 ratings due to favoritism/hatred).
Or if we didn't have to worry about that, then we could just trust each other to give ratings as we buy/sell from each other on our threads in trade forums. The thread itself can serve as a "legitimate source of proof" if the buyer/sell made the purchase after making their bids on the sale/buy thread. This could be designed so other members were able to view this rating and/or comments, and who gave them the review. Obviously it wouldn't have to be required, but all of the members who are concerned about buying from somebody who may be using an alt to fuel the bid war, could have a peace of mind if they saw that the seller has great ratings based on other's experience of buying from them.
I don't quite see the use of a "Scammer Black list" since this forum isn't as active in pre searing... because of the never ending questions: "What is a scam" and "how does one actually scam when both parties have to hit accept?" If you've made it to this site, then the odds are pretty good that you're not going to be somebody who "sells a q8 crystalline 15%stance for 1750ecto". Figured I'd use this memorable moment as my example xD