I am not sure if this comment was directed at me, but the "genuine question" was a genuine question, not rhetorical :) And the answer I was looking for was "the

I am not sure if this comment was directed at me, but the "genuine question" was a genuine question, not rhetorical :) And the answer I was looking for was "the payment cards probably use QR codes instead of magnets/IR/RFID/etc."