A nasty misunderstanding based on an accidental kanji/mahwa pun in a skit performance by some Japanese students in a university in Xian resulted in a large and violent anti-Japanese riot in that city. Here's a first-person account of what happened. As far as I can tell, a stupid "we love China" skit by the Japanese students (they were there learning Chinese in some sort of exchange program, it seems) resulted in an accidental pun that jingoistic local students took as disparaging. I'd hope that this sort of thing would stand as a lesson for those folks who think that American nationalism or American racism is somehow unique or exceptional.
Oops. Via Gweilo's Winds of Change China Wrapup.