I've seen the fake $100 bills that CLEARLY state "Prop Copy ... for motion picture use only". Often handed out as a gag, or used during play "casino" parties. I've even seen a guy throw out a stack of them at a go-go, thinking he was being funny. At a quick glance, they look real, until you zero in on the aforementioned stamp, which you can't miss. But furthermore, they don't even feel real. It feels obviously fake. So I'm not sure what this guy thought he was going to accomplish. Even if I wanted to play a joke on someone, I certainly would never try to take it to a money exchange or a bank or attempt to actually use it for a transaction.