Is multiculturalism wrong only when Islam is the other culture ? Islam is unique among the religions because it has political, social, and legal "spheres of influence", because of this, I would say Islam is not a simple faith based religion, by embracing it you also must embrace its political, social, and legal philosophies.
The majority of the Muslim world today however, does not strictly adhere to all three sides of a true Islamic society's way of life, in fact many are secular, and a select few are democracies, which is good and all, but even in these countries, governments and political parties must always fight or debate this "darker side" in their societies, and they don't always win. In a secular democracy, this dark side takes the form of a right wing political party, and in a secular dictatorship, the form of an extremist terrorist, what i'm trying to say is, political Islam will always have a "representative" and will stay as long as Islam stays.
If you go to one of these countries, ask random people on the street if they would support the implementation of Sharia law, more than half would say yes, these laymen don't understand the consequences of such an action, they don't really understand what Sharia law is, it's just because the word sounds "noble" and good to them, and when a real lunatic gives them the chance to support him many will do, either democratically or not.
As to religious police in Sweden, the phenomenon is really weird, because most muslim countries don't implement such a thing, excluding Saudi Arabia and Iran, the Swedish government thinks that it is practising tolerance by allowing minorities to "practice their culture" without imposing western culture on them, but what they don't comprehend is that this form of Islam they're allowing to exist, is kinda Fascist, true Islam, as per the Quran and the sayings of Muhammad, wants to control every aspect of your life, true Islam doesn't tolerate differences, and apostates are executed, non-muslims are below muslims in this life and the next, true Islam is not free, is not democratic.
In the same sense Nazis and far right groups are not tolerated in Sweden, then political Islam should be approached in the same manner. I was always sceptical to the idea that political Islam will some day have a voice in the Swedish parliament (as a consequence of increasing muslim population ?), but if we don't have the courage to criticise political Islam, then religious policing might someday become normal in the eyes of the public.