The answer is that this is not very safe, and the security measures of bank cards in the United States are very backward. In fact, in China, you can also choose not to use a password, but only to use your signature. It is indeed the responsibility of the merchant to consume according to the signature. If it is stolen, it can be retrieved through the bank. When many foreigners spend money in American shopping malls, the cashier sometimes asks the cardholder to show his passport, and then checks the certificate and card name before swiping the card. Credit card theft in the United States is particularly serious, and the security of bank cards in the United States is not good. Chip -pin chip cards were popularized in Europe ten years ago, and now many places in the United States still use credit cards with only magnetic stripes. But now all the new cards issued by big American banks have become cards with chips. However, although this card has a chip, it can't be regarded as an EMV card with a chip plus a password, but a chip plus a signature card, because the card password is not verified during the transaction, and the consumption is confirmed by signature.