Though I live in Canada, I was originally born in Poland. And let me tell you, it's not only the people from Poland that troll others, I've been trolled by users from Russia all the way to Spain XD
Heck, the other day, some french users powerplayed killing me, thinking I didn't understand french (I do, so joke's on you guys).
That's not to say that I don't troll, my techniques are a bit different and not as offensive as someone insulting others.
Sometimes when I'm bored I'll go ahead and write a huge paragraph in French to someone and they're like "I'm sorry, what?"
Or I'll go around and write replies in Polish to other's questions such as "Are you feeling well?" "Tak, czuje si? coraz lepiej" "... ?"
Even going up to people and asking random questions in Latin or Prussian (With Google translate and Prussian dictionaries of course).
So yeah, trolls come from every country whenever someone's bored, heck, even me, although I try to keep it as low and the least offensive as possible, just writing in uncommon languages gives me enough release. To sum this up, it's not right to say that everyone from a certain area is the same just because a few people act that way. A few people do not represent the entire populace and they shouldn't either.