The new head of MI5 launched a robust defence of the techniques used by Britain’s intelligence agencies in his first speech since taking the job and warned they would not be able to sustain current levels of counter-terrorism work without the help of surveillance from GCHQ.However, Sir Andrew Parker also acknowledged that the growth of the internet, technology and big data was “transforming our society” and that significant choices had to be made about which capabilities were required to track terrorists in this new and different world.
http://www.theguardian.com/uk-news/2013/oct/08/gchq-surveillance-new-mi5-chief