> To wit, if U.S. issuing banks (i.e., banks that provide credit cards to U.S. consumers) were to refuse to settle certain transactions (e.g., card-not-present

> To wit, if U.S. issuing banks (i.e., banks that provide credit cards to U.S. consumers) were to refuse to settle certain transactions (e.g., card-not-present transactions for a subset of Merchant Category Codes) with the banks identified as supporting spam-advertised goods, then the underlying enterprise would be dramatically de-monetized. > Furthermore, it appears plausible that such a “financial blacklist” could be updated very quickly (driven by modest numbers of undercover buys, as in our study) and far more rapidly than the turn-around time to acquire new banking resources—a rare asymmetry favoring the anti-spam community.