The case of the recent London terrorist attack, has been processed by the chattering class who are proclaiming that the attack has nothing to do with immigration. They always are, because if it was otherwise they would have to accept that there were valid criticisms of immigration.
Thus, Matthew d’Ancona has written: “As we now know, the attacker, Khalid Masood, was British, born in Kent and brought up as Adrian Russell Elms. His story is one of radicalisation, the question being when and how he embraced extremist Islamist ideology: the path that led him to an act of murderous violence has nothing to do with immigration”: https://www.theguardian.com/commentisfree/2017/mar/27/brexiteers-immigration-promises-unravelling.
The problem with this argument is that it ignores the reality of second and later generation children of migrant de-assimilating, rejecting British culture and values, in favour of the values of their real homeland, or even imagined community: http://www.theoccidentalobserver.net/2017/03/born-in-britain-mass-immigration-and-the-twilight-zone/. With the numbers of home-grown terrorist incidents growing, it is no longer even moderately plausible to be mechanically assuming that being born in a country will assure allegiance to its core values. It is yet another myth of immigration.