If you want to truly understand what kind of problem that the UK faces in trying to deal with Islamic extremists who use the freedoms of the West and take full advantage of the policies of multiculturalism to shield themselves and their hostile activity from the authorities, then I recommend you watch the following episodes from the UK's Channel 4 documentary show Dispatches. Here's the following links to the six part series over at YouTube:
Part 1: www.youtube.com/watch?v=peFQWuk4nuo
Part 2: www.youtube.com/watch?v=MuCLC8kjWCI
Part 3: www.youtube.com/watch?v=x5t5EqWX92k
Part 4: www.youtube.com/watch?v=yMztM0Z7BYE
Part 5: www.youtube.com/watch?v=V4Zv3BUmwqs
Part 6: www.youtube.com/watch?v=KvjvNScmTQA
I have to say that these episodes of Dispatches as well as Melanie Phillips's Londonistan provides one with an eye opening look at how a full embrace of multiculturalism out of a fear of offending can have a horrific impact on a society and its well being.