Fun Luhn fact: you can transpose any two odd or even indexed digits except the final check digit in a credit card number, and still get a card number that passe

Fun Luhn fact: you can transpose any two odd or even indexed digits except the final check digit in a credit card number, and still get a card number that passes a Luhn checksum. You can use this to give cybercriminal scammers card numbers that probably aren't connected to any actual account.