Debit and credit cards
Using debit cards as credit cards

It should be impossible for anyone to use a debit card as a credit card. If debit cards had 17 numbers

and credit cards had 16 numbers or vice versa, I think this would solve the problem with unauthorized users using a debit card as a credit card. The carding machine would alert the cashier if a PIN is needed. If both cards required a PIN, that would be another solution. It shouldn't be so easy to use a debit as a credit card!