[@TheHangedMan] that's not limited to Americans exclusively. People in general are asshole when it comes to topics they care strongly about. 
As a Canadian cashier near the border I get self entitled doucheflutes all day.
"what do you mean you don't take American currency it's legal tender."
"in America yes, but this is Canada"
"so"
"do you take Canadian in America?"
"fuck no. Its America. Get out money or leave"
And IM not allowed to tell them off. Imagine that all day 10 hours a day

That's the same kind of stupidity you will find anywhere. Not exclusive but oh so similar.