So if you spend money with someone else's credit card abroad, most merchants will check whether your signature is consistent with the signature reserved on the back of the credit card, and some merchants will even check your identity (such as checking your driver's license, passport and other personal documents).
Because in foreign countries, the division of responsibilities is more detailed. If the merchant fails to fulfill the verification obligation, the cardholder can ask the bank to cancel the transaction at any time. Therefore, foreign merchants generally check the signature and other information.
If you use someone else's credit card, you may be found to be fraudulent and not allowed to use it. Even in some countries with strict legal systems, businesses will call the police directly.