Because a receipt is a forcing mechanism for the system to close the transaction. No sane system allows for continued charges on a card when a receipt has been

Because a receipt is a forcing mechanism for the system to close the transaction. No sane system allows for continued charges on a card when a receipt has been generated without re-authentication & re-authorization. Plus it gives me, the customer, additional leverage in the case where they do screw up. I printed the receipt at 0944am. At 0945am someone withdrew $100. No new authn/authz. No jury would allow these withdrawals to stick on the original account.