Cory, there are obviously reasons why we have many Pakistani immigrants in this country but not many Moroccans, for example, whereas in Holland, it is the other way round.
But that's hardly relevant to the 'man on the street' who is unhappy with the change to his neighbourhood.
Fllippinada, when I lived in an area that was historically Christian, in a Muslim country, in-country migration resulted in many people converting to Islam. In this case, I'm quite confident that the impetus for people to convert to Islam has come as a result of immigration. There is no significant White British Muslim community.
Gordy people born in the UK in many cases retain a specific non-British identity. For instance, British Chinese people, though speaking with a British accent, may retain strong ties to China. In the case of British-born men of Nigerian descent living in Woolwich, the identity is not specifically British, but British and Nigerian, since there are numerous Nigerian shops, restaurants, new Nigerian immigrants, and so on in the area.
Few White British people would know what fufu is, but I would imagine that nearly all British Nigerian people do. I know lots of people of immigrant background, they have British passports, but they also retain an immigrant identity, and proudly so.
That doesn't mean however that you can say 'ah but they were born in Britain'. Yes they were, but many things about them are of immigrant origin. Not bad or good, but White British people in these areas may say, 'actually I prefer things how they were'.