Ground to air missiles to be sighted on Shooters Hill

[Streetrod]

As is being reported today the MOD are suggesting they sight ground to air missiles on Shooters Hill in London as an last line of defence for the Olympics.

Now correct me if I am wrong but if a terrorist decides to fly a plane into an Olympic stadium are we really going to shot it down over London so sending the wreckage to come down on another part of London or am I missing something here?

And who would take responsibility for making the order?