Using terms that sound like something out of a spy novel - such as MIIs and the Luhn algorithm - you can decode parts of a credit card number and even tell whether it’s fake or valid. You can do that because credit card numbers aren’t random. Here’s a fun trick to entertain friends and win bar bets: Guess the first number on somebody’s credit card tucked away in their wallet. Watch Video: Americans now have the highest credit-card debt ever
