Generally notorious for this behavior are Italian and Spanish men, and even men from India, Pakistan or Bangladesh I find absolutely shameless in trying their luck when a woman is around alone.
Being a foreigner in a country makes you stand out more and ass groping is most common in clubs all around the world. I normally ignore.
Japan seems to have come up with a different way to deal with this problem: Japanese women are flashing a text message that says: “Did you just grope me? Shall we head to the police?” to deal with being groped by perverts without attracting attention.
What I imagine: man pinching backside of woman, woman looking for “anger” button on phone that downloads a message, woman turning around and shoving a phone in face of groper.”
I don’t know if that’s better than shooting him a dirty look and ignoring — as it sounds like bit of a delayed reaction — but the cell phone application has recently been ranked in the top ten.
I suppose if you were a foreigner living in Japan, this would be perfect until you learned to speak the language — but I think dirty look followed by ignoring is universal language that says “bugger off you sick pervert,” no?