What does it mean to send text messages when credit card (debit card) transactions are abnormal?

Credit card (debit card) transaction is abnormal. The bank sends short messages to remind users that credit cards (debit cards) are under risk control, and users need to use them according to regulations. For example, don't swipe credit cards (debit cards) on POS machines that skip codes, and don't swipe credit cards (credit cards) at suspicious businesses, so as to keep the diversity of consumption as much as possible. Only in this way can it help to lift the bank's risk control.

However, after receiving the SMS, the user fails to repay or illegally uses the card, and the risk control will be further strengthened. Finally, the card may be frozen and cannot be used.