As you know, in that part of the world, people are tought a certain version pf relative morality: one set of rules applies to Muslims and another to the rest of the people. To lie to a non-Muslim is not a lie. To take the virginity of a non-Muslim girl is no big deal. In fact, they often say that "all non-Mulsim girls are whores," hence must be treated as such.
I would be very surprised therefore if there was a single Muslim girl among the victims. From the standpoint of these brothers, they committed not much of a sin.
Culture-enrichers? That's a good one. We live in the age of implosions. The Soviet Union has self-destructed, and the reason for that is understandable. It is harder to understand why the West, having proven the superiority of personal freedom and markets, is set to destroy itself also.
Culture-enrichers? Bringing in ethnic food and Persian rugs is not the same thing as, for instance, refining Dutch law, the ancient and proud institution of corporate enterprise, and tolerance and respect for democracy.
"The Soviet Union has self-destructed, and the reason for that is understandable."
It must be added here that East Germany fell because of the activists Lutheran church and Poland fell because of the activist Roman Catholic church. Religion can be major source of revolutionary fervor. So it is most possible that lets say, Denmark, England and France could fall because of the Islamists in the next 10-15 years.