it is a very interesting question, because 20 years ago a chap called david copeland, who was a terroriste—grown terrorist — you might him, from central london and he did some terrorism in brixton, just around the corner, but you are right to point out that not surprisingly central london has the greatest intensity of armed police. obviously, you have the royal family there. you have the politicians in the house of commons and so on. when you move out of london towards the suburban area, it is still classed as central london or on the threshold and in the middle of london is an even tighter area known as the government security zone, but the fact that it has now without, if that is a case, is slightly worrying. there is at least one report that i have seen saying this could be the conclusion of a car chase which puts a very different emphasis on it. we have seen some of those reports of a car chase. we have even seen one report which we were reporting on the bbc breaking news page suggesting that one of the cars might have crashed, and that potentially leads to the suggestion that streath