I had a lot of Asian exchange students in my business grad student classes, and most of them had American names (no Brians that I knew of, actually). There was a Tom and a Victoria, and one kid who went by "Ig" who may or may not have renamed himself that. I always wondered what thought process went into giving yourself a new first name for your time in a different country. Many (myself included) offered to try to pronounce their real first names a few times but they always politely declined, which made it far easier for everyone.
in my experience it's always brian or david. i find it annoying especially since these names are not even american. the only american names are pocahantas, geronimo, and such.