[tappio]

Visa and Mastercard are card schemes. They are just moving the money between financial institutions. The issuer (which is the financial institution from where the credit card was applied from) is providing the credit line=they own the money. The scheme ensures that the other parties always gets their money, which is why their business is really dependent on good fraud detection algorithms. The payment schema will just freeze the settlements during the dispute, but if evidence is found that it was fraud, they will lose the money. This of course happens all the time, but it is just a pricing issue. Visa charges license fees from issuer and acquirer, and every transaction costs for the merchant around 0.5-5% depending on the card.

[tappio]

Had to check again, visa and Mastercard actually don't carry the risk in this scenario. It's either the acquirer or issuer. Scheme acts as a judge and decides who's fault it is. However, now that 3d secure is in place, if both issuer and acquirer support it, there are really few frauds. If they don't, the risk is on the one who did not enforce 3d secure.