> 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.
I called MasterCard twice and both times they a) guessed that I was calling about content on Steam without ever mentioning Steam b) said that they only restricted "illegal adult content" and have "standards based on rule of law". Said absolutely nothing about protecting the brand. Also couldn't say if said "standards" were actual laws or MasterCard's own (legal) standards.
Good argument to record any calls with them and submit the recordings to the press
You don't really have to record the phone call. If anyone in the press wants to hear them saying that they don't block legal content, call them and ask about Steam. They have a ready-made PR response that they will read to you.