Merchants do not have access to the CC numbers, the payment processor does. And even if they did, what you're proposing would be far more work than it's worth. If you wanted to, you could get a list of email addresses from accounts that have submitted excessive chargebacks, and put in some form validation logic that prevents them from making further transactions.
Sounds like a simple service someone could provide. API with two endpoints: one that takes the hash of an email address + details about the chargeback (dollar amount, etc.) and another that returns some kind of score based on the same email hash.
Merchants could opt in to the database by agreeing to share chargeback data. If someone on the list tried to sign up, the merchant could either block the sign up or present an alternative/safer payment method (e.g., direct deposit).
All that being said, no idea if it'd be worth it for merchants.
anyone want to help me build this? first we get traction on hackernews (as we clearly see demand for it), join YC, sell to startups, serve ethoca their lunch, then potentially get acquired by Stripe?
Merchants probably don't have enough information to do that themselves, but it does seem like a service a provider like Stripe would be happy to provide.
i run a startup. I would be extremely willing to join a shared blacklist API. If this comment gets votes, I will make a service and populate it with data from our end.