Credit cards originated in the United States and developed in Europe (when European currencies were not unified before). When you swipe your card in Europe, you will pay special attention to the signature style. If the signature is different, you will be asked to show your passport and other corresponding documents. Early credit cards didn't have passwords, but only used signatures. Under this condition, the signature is extremely sensitive! Therefore, it is not easy. Tell me a personal experience. Take a passbook to the counter to withdraw money, because the signature is different from the handwriting kept in the banking system (Chinese writing is difficult to distinguish), and you are required to provide a passport to check your identity. The passbooks here also have passwords, and they still need to check them by signing. Of course, the strict requirements of the banking system are no problem. Merchants are really hard to say, but they can only say that they are stricter than domestic ones.