the machines you are talking about were called "reader writers". They would record the data on the back of the strip. Gas stations are notorious for using these when you give the attendant your card. The issue was if ever used in a store, the number on the receipt would not match the number on the actual card so an astute cashier could cause an issue. They would record data from the 'readers" and then put them on the strip of a stolen card that was no longer good. The true pro's get real cards with all the personal info and methodically make charges without c reading a fraud alert. Remember, camera's are now everywhere.