Hmmm... sounds like an interesting startup idea, curate a list of bad buyers and sell access to it based on a monthly subscription. The catch being that whoever curates the list would have to do a thorough job either vetting complaints or developing a statistical model that predicts if someone is a jerk at a higher rate than the average consumer. There are issues with this idea of course, it might be more expensive to run the service than sellers lose in revenue, you're liable to tick off both sellers and buyers by attempting to be an unbiased mediator. You could also land in hot water if a minority group ends up having higher than average rates of getting black listed.
I think it would almost have to be someone like Stripe or Paypal, such that they have a broad enough view into the buyer. They would get data via chargebacks versus just seller initiated data.
Personally, I think credit card companies should send back something like "percentage of purchases with a chargeback" and let us decide how risky we want to be.
You could also function as a broad returns resale company, front a portion of the money for the return fix/dump products in house and resell them at a discounted price. Then adjust the percentage you refund the seller based on what type of item it is and how much of there stuff comes back unsalvagable. Target resale at the developing world/people on shoestring budgets/startups.
