Dale Cregan used grenades and firearms to kill two cops and a father and son. He was a white non-Muslim Englishman.
Raoul Moat went on an extended rampage, shooting people dead and blinding a police officer with a point blank shot to the face. He was a white non-Muslim Englishman.
Derrick Byrd was a cab driver who took a shotgun and went on a rampage, murdering anything that took his fancy. He was a white non-Muslim Englishman.
For every one instance of Islamic extremism that you see today, I could spend twenty minutes and find fifty instances of berserk violence from a white, non-Muslim Englishman.
You're making the mistake of tying an entire religion to very rare acts of violence from criminals and calling it a problem. It's religious delusion and you can find examples of Christians doing the same thing - look up Nicola Edgington this year alone. Stabbed her mum to death due to religious delusion.