It's pretty crazy how much fake USD's exist overseas...
Hell, it's a little crazy how many bills HERE are fake. I've encountered two bills -- a 10 and a 20 -- that smeared when they got wet. Never encountered one fake bill in my life until I got to Atlanta.
I used to see them all the time when I worked at Six Flags Magic Mountain back in the 70s. They were easy to spot. It was often a clueless foreigner. Someone once explained to me how much bad counterfeit US cash is floating around the world and how foreigners often bring it here to spend -- to great surprise.