An early scam was to buy something at Home Depot on the card, record the purchase, wait until supervisor and RA signed off, then take item back to HD and return it for cash reimbursement. (HD would do that in those days. After the scam came to light they would reimburse onlyto the original card).
FYI, this scam is still a thing. They just return stuff without a receipt and get a gift card, then sell the gift card for cash. This is the primary reason why places have started asking for your DL/ID, phone number, etc to return items without a receipt.
This is also a common shoplifter trick. Lots of places have cracked down on it in recent years though.