Most of the slot cards I've seen have that the card belongs to the casino and must be surrendered upon request written on the back of the card. The outlets in the casino are supposed to ask for photo ID before redeeming anything, but unfortunatly that doesn't always happen, so some places don't like you taking their cards. The magnetic strip has an OCR number (Optical Character Recognition) that links the database to that particular card. No other info is stored on the card, to my knowledge. Hope this helps.