Add a 6 digit PIN to a credit card

For a long time, I have been worried about the use of credit card. It seemed that any body can quote the credit card number, expiry date and CVV to get a transaction through. All the information, including the CVV, appears on the card.

I asked why does the bank not ask the customer to provide a 6 digit PIN for the credit card, just like it is used for the ATM card?

Here is the answer.
http://www.tklcloud.com/Feedback/feedback2.aspx?id=2133