This old 'youre patronising' attack is it?
If you want to close your eyes to the fact that communities like this do exist and they do act in these ways, because it doesnt fit in with your political beliefs, then be my guest.
You wont mind if a load of Anti Nazi League students parachute into Barking and Dagenham then will you, because white working class communities dont exist, only groups of friends and family. In fact, not parachuting Unite Against Facism people in would be patronising.
Left groups (rightly imo) get criticised for the above mistakes of some anti fascist groups, and the exact same is true when dealing with muslim areas.