Just received an email, I think that I should share with you all.
The story is as following:
This is the true experience of my colleague and myself during last Saturday. We went to a restaurant during tea time, consumed roughly only dozens of dollars, she used his credit card to swap the payment. But when she was signing the printed receipt, she felt those receipts were much thicker than it used to be. Then she looked more onto it and found that there was another different receipt below of the one she was signing while the amount is several hundred dollars (the waiter deliberately used stapler to set two receipt together).
Should be aware that the receipts are all single-Carbonless Paper, and she just need to sign the toppest receipt, those below will automatically printed her signature. Even if fraud was found after that, we will never can find a reason to argue because it is autographed by our own signture. How terrible it is! Fortunately, my colleague found out that earlier. My colleague was stern and asked the waiter that why there was another receipt that not belong to her while that receipt was printed her card number as well. The waiter was nervous and teared off that receipt immediately while explaining that probably is cashier mistake to swap wrong card.
But let us think more about it, even if they swapped wrongly, it should be the same amount, why there were two different amount with same card number? And they will have what benefit throughout this?
Later, we came to understand that they have such a operation: There are many customers want to pay to hotels while oftenly, that is at the same time when few tables want to settle bill. While some tables are settle using cash term, and then those staffs would use others' credit card to swap those cash term amount. If there was nobody discovered and signed few different amount receipt at the same time, those "running cash" will then surely fall into the waiter's pocket. Even if we report to police so, as that is the receipt we signed, they can just simply deny that they don't know anything about it.
So, beware when you are swapping the credit card, be sure to check your own swapped amount and receipt.