> Mastercard's Rule 5.12.7 relates to "illegal or brand-damaging transactions," and states:

> A Merchant must not submit to its Acquirer, and a Customer must not submit to the Interchange System, any Transaction that is illegal, or in the sole discretion of the Corporation, may damage the goodwill of the Corporation or reflect negatively on the Marks.

I didn't expect they had such clear rules expliciting they can ban any kind of transactions they don't like or would make them look bad, regardless of the legality of it.