See #124.
There's loads of stuff going on in life which should not and does not get given out to feed the great unwashed's 'need to know'.
Often - I suggest - we get told too much.
e.g. The French policeman who died after swapping places with a hostage and got slaughtered by yet another misinterpreter of the Koran the other week was widely reported to have left his phone on silent but transmitting so that officers outside could keep track of events. Can't see that happening again. Nice one journalists.
If you honestly believe that the evidence given to HMG and friendly states about the poisoning is solely that which you have read in the news or heard on TV, i.e. is purely circumstantial, you are very stupid and the £2 billion a year spent on the Single Intelligence Account (SIA) is wasted.