The strange thing about Norway's xenophobia is that the haters are responding to a non-event. According to this very sharp piece, Muslims make up only a small percentage of the immigrants, with most coming from other Scandinavian and East European countries. Muslims serve as a convenient target after 9/11, but there is no reality to the fear that Muslim immigrants might have much weight in the political and social systems. Other countries in the region have seen a bigger flow, so the resentment is easier to understand (not approve, just understand).
This is not too surprising since extreme right-wing political movements do tend to focus on imagined enemies, such as the UN's black helicopters, but it speaks more to alienation in general rather than on immigration. We should not say that their choice of stated enemies do not matter, but the problem is not so much immigration, at least in the Norwegian case, but the social and political dynamics that leave folk so outside the political system that they need to blame a pretty small group of immigrants for whatever ails them.
Immigrants are easy to blame and to target, but we should not be distracted by the blame-casting. Nor should we see this as entirely new and a product of globalization or the internet. Folks have long used outsiders as scapegoats and right-wing extremism is not new to Norway either. So, before we focus our attention on that which is new, we might need to consider older, more basic political dynamics (including that the political spectrum is really a circle where the far right and far left merge).