My sister used to work for a Prop studio, and one Christmas she gave various members of the family fake $100 bills. They said very clearly "For Motion Picture use Only" on them, and it was quite obviously not a real $100 bill. My brother jokingly decided to give it to a cashier who then proceeded to start counting change. Embarrassed, he had to explain to them that it was all a joke, and the money was fake.
The bar for being a cashier isn't all that high. I bought a gift card at an IKEA in Shanghai for 100元 (about $16). IKEA's web site seemed to indicate that their gift cards couldn't be used across countries, but I took it to a cashier at a store in California to see if that was true. The cashier happily informed me that my card was loaded with 100 dollars. When I expressed surprise, she gave me a receipt that correctly showed 100 CNY.
