Let me explain, I take payments from costumers in an office enviroment. For the sake of clarity I photocopy the bill as their reciept for their records with the check they used to pay for it and occasionally I'll put cash on the glass out of habit.
Now, my copier broke so I am using my co workers HP Officejet Pro 8600 and it so happens I threw money on there and proceeded to get faield copy after faild copy after the lamp got half way down the document. I moved stuff around and eventually took the money off and it copied fine. I then started putting random bills on the scanner bed and it would immediatly cancel the copies after maybe 1 cm worth of picture making it on the paper.
I am well aware that copying money is countefitting and assume this is just a counterfitting countermeasure but damn if it didn't blow my mind, can anyone explain to me how this feature would work?