I went to grad school in the USA. I bought the international version of a few books that were going to be used in class (knew beforehand that the recommended lectures weren't written by any faculty member at such a university), but that didn't stop the professor from going aggressive and saying that my books were banned from the classroom because they aren't the USA version. When I told the professor what the difference was between me buying a text book for $15 instead of $200 and a Fortune 500 outsourcing entire departments instead of hiring USA employees?

Interestingly, my books weren't an issue. Yes, I gambled being publicly labeled as a troublemaker in my engineering department (probably I was labeled privately within faculty members).