The answer is that it is not very safe. The bank card security measures in the United States are very backward. In fact, in China, you can also choose not to use a password and only use a signature to make purchases. It is indeed the merchant's responsibility to make purchases based on the signature. If it is stolen, it can be recovered through the bank. When many foreigners make purchases in American shopping malls, cashiers sometimes ask for the passport of the card holder. The cashier checks the ID and the name on the card before swiping the card to charge. Credit card fraud is particularly serious in the United States, and American bank card security is not very good. Europe has popularized chip-and-pin chip cards ten years ago, but many places in the United States still use credit cards with only magnetic stripes. However, now all the new cards issued by major banks in the United States have become cards with chips. However, although this kind of card has a chip, it cannot be regarded as a chip-and-pin EMV card, but can only be regarded as a chip-and-signature, because the card password is not verified during transactions, and the signature is still used to confirm consumption.