A no-swipe credit card is a credit card equipped with a radio frequency (RF) transponder that allows for purchases without the need for passing the card through a traditional magnetic-stripe detection machine. The card holder can simply come within approximately 0.6 meter (2 feet) of the checkout terminal. The terminal emits a tone or displays a confirmation when the transaction has been authorized and payment made. No-swipe credit cards use technology similar to that employed by RF identification (RFID) devices. The chief advantage of no-swipe credit cards is the fact that they save time. Although the actual amount of time saved per transaction is rarely more than a minute, this can add up over the course of a day at a high-volume retail business and can significantly reduce the time spent by customers waiting in long lines. The technology was originally introduced for use in gas stations during the late 1990s. Despite their convenience, some engineers warn that no-swipe credit cards pose a higher security risk than conventional magnetic-stripe cards. In theory, a thief might steal card information by standing next to a victim for a few seconds while operating a concealed RF card reader. Security and privacy advocates fear this could exacerbate the general problem of identity theft. Technology similar to that used with the so-called Chameleon Card may mitigate this risk