Well, for one, I was curious why you chose a picture of Dubya as opposed to Barack Obama or someone in the British Government. Anyway, why should we be surprised? You lack any legal document like the Constitution and the Bill of Rights. The citizens cannot bear arms or even trivial items like pellet guns, there's no freedom of speech to criticize the violence and oppression by the practitioners of Islam, and so forth. I read an interesting story that the British government had a program to install CCTV cameras in thousands of private homes to make sure kids are "eating their vegetables and going to bed on time" in families described as "antisocial." So I'm not surprised they will destroy documents showing what the NSA does this when the British have been part of this surveillance since the Cold War and do these things same activities in regard to the British people.
This will harm the freedom of press in Britain and of course the freedom of speech. Guardian has a right to publish the material snowden gave them. People must have a right to know whats going on behind their back.
By destroying files of information british government proved how free the media in britain.