Likely it's those selling predominantly adult content. Amazon's offerings are not predominantly adult in nature. Nor are Netflix's. Presumably, if there's a higher occurrence of fraud with those merchants whose wares are predominantly adult in nature, processors consider these types of business more risky. However, they (processors) already have a tool at their disposal to combat fraud: the rate that's charged to the merchant for taking payments. My understanding is that riskier businesses tend to pay a higher rate for their card processing as kind of an insurance against (inevitable?) fraud. And then it would be my opinion that an account shouldn't get terminated except due to actual (excessive?) fraud.