I believe it came from this post (the one that hit r_all), archive. There is some discussion about it in this downwoted thread, archive (look at the comments). As I understood, it was posted by a user from KiA initially, but since it went into metaphorical/exaggeration territory ("put you to death", "war", "slaughtered on the altar of social justice" - metaphors, that will look too edgy for an outsider that didn't see all "I want gamers gassed" anti's posts), it's being milked by trolls.