I'm gonna go with troll...
I remember when the "all Brazilians are trolls" attitude started on the NA servers. Never had a lot of Brazilians in my games until the whole "huehuehue" meme, and then suddenly "Brazilians" everywhere.
What's happening now with all the supposed "feminists" that started appearing as it became popular to bash all feminists as sexist looks really really similar. Could be a highlighting effect, but I don't believe there are even remotely as many extremist/sexist "feminists" as it would currently appear.