"No processor, no matter how good, and no matter how iron-clad their policies may seem, will take 100% liability for scammers. Yes, even PayPal, with their “100% guarantee against fraud.” This is the reality. There’s a lot of fine print for them to hide behind."

My experience having a merchant account that accepted credit cards was that payment processors accept absolutely NO liability. The merchant pays 2-3% (more for AMEX) and is usually on the hook for 100% of the fraud.