Wow! i'm pretty shocked by what ppl have written. I'm a British Pakistani, and yeah there are Paki's here that I assume do get into trouble with the law, but I wouldnt go so far as to say that 90% of them are bad.
Maybe its cos I live in London, I really dont know what the asian communities are like within places like Birmingham and Manchester, but I know very few ppl who fit that description. I didnt live in an unsafe neighbourhood, i remember going to the local park alone when i was 7 but times change and its become more dodgy now, but thats happened everywhere really.
I'm from an average middle class family, and most of the British Pakistani's I know are the same, that includes Pakistani's I've met at uni from other parts of UK. Of course you're gonna get British Pakistani's who are poor or unemployed and the 'gang culture' is just a by-product of that, but its something you find in white, black and chinese ppl. And as for segregation...
Its always going to be problem. I attend a uni which is a very racially diverse (not sure if thats the right phrase) but you still see cliques developing with just white ppl, or just chinese etc. But that doesnt mean to say we dont interact with other races, its just easier to connect with someone else from the same backround who understands the nuances of our culture.