I can see it now. A miss-heard clearance, a read-back garbled by others transmitting on a heavily congested frequency, a fluffed frequency change and... Boom! Bit's of aircraft etc. are now strewn across tracts of London. It will have to be that or the Titanium curtain protecting "us" will be worthless. It takes approx. nine minutes from LHR and only three once airborne from LCY to get to that place I probably can't mention because of The London Olympic Games and Paralympic Games Act 2006. That means a decision will have to be made by somebody within seconds to either shoot or hope that it's just an innocent mistake. Have you ever heard of a politician (with the exception of the warmonger Blair) making any decision that quickly? So the decision will have to be made by the military.
I'm so glad I'll be paying for an event I can't (afford) go to, I can't mention because of a temporary Act designed to protect greedy sponsors, one which will potentially bugger our lives for a few months but one I'll be paying for... I'm so glad I live in a free country.