> > many places, for example, will accept Visa and Mastercard but not Discover.

> But that's explicit and the same for everybody. If you accepted Discover from somebody and not from somebody else, THAT would be discrimination.

> Discriminating the credit card somebody is using without telling anybody... well, could still be discrimination. Younger people could be more prone to use an Apple card, couldn't them? Can you demonstrate the "feature" you're discriminating about can't be tied to age, race, gender, etc?

FYI discriminating against people on the basis of age is not illegal when applied to youth, at least in the United States. This is obviously the case as we use age as a gate for many privileges.