The OP has written extensively about this subject in the past, and I get the sense that he is intimately aware of the risk of false positives, however catching

The OP has written extensively about this subject in the past, and I get the sense that he is intimately aware of the risk of false positives, however catching a high volume of fraud could for him literally be the difference between staying in business and not. His fraud tolerance is going to be much much lower than a large vendor.