gift cards, not just for offshore black market call centers running "Pay the IRS in gift card" scams anymore.
The system is often more reliable than the staff. I bought a gift card from IKEA in China and wanted to see what would happen if I tried to use it in the US. It worked fine, in theory. But when I asked the American cashier how much was on my card, she happily reported to me that it was $100. (It wasn't; it was ¥100.) The receipt she gave me, though, correctly listed ¥100.
Was there some kind of mix up? Are they laundering their money using foreign currency? Or does US Ikea not understand the difference between Yen and Yuan?
I am not aware of any such distinction being drawn in reality, though.