Re: London - riots
Some people are much more attached to their culture than their religion. From the outside perspective both are just patterns of behaviour. The same reason you dont see many blacks in the City also applies to why if you have a long beard and are perceived as religious you might face difficulties in getting a job there.
Individual action is a ‘big’ part of it, but the ghettos persist because the government doesnt do whats needed? If individual actual is the big part then surely government action is superfluous.