http://www.economist.com/blogs/graph.../islamineurope
Neat chart showing the actual Muslim populations of Western European countries vs what people polled thought they were. Also the amount of terror related arrests and how many of those were religiously motivated vs other reasons. Didn't really have to point it out but the far right is really good at fear mongering. People in France thought Muslim populations were 31% while in reality it was only 8%. Most terror arrests come from other sources like separatism, according to the article.