Ever ask yourself why the merchant would spend money on this? I mean there's no risk to the merchant. If stuff is bought with a stolen credit card then the credit card company or the bank bears the risk.
No, it's the merchant who bears all the risk. If someone disputes a charge, the merchant's acquiring bank writes a friendly letter asking for proof of the card-holder's authorization, eg a signed receipt. If you can't offer evidence that it was authorized, then you get a chargeback (ie they deduct the purchase amount from your account) and you are out of the value of whatever you mailed out to the customer.
When we sold stuff online, obviously we don't get physical signatures, but normally we could convince the customer that they had made the purchase (normally they forgot, or didn't recognise our name on their credit card bill) and the customer cancelled the dispute.
Why would the bank voluntarily eat the loss for fraud/disputes?