Its top of the page on the Guardian, so hardly breaking news, but IPPR have released a discussion paper written by Sir David Omand on the above topic. Its available in .pdf from here.
It deals with issues of database intelligence, and how this will alter the model of the intelligence agencies - which frankly, considering what the job of GCHQ is, and what foreign intelligence agencies such as NSA have been doing for years, is somewhat behind the times.
However, he does flag up a set of guidelines for intelligence use. With proper deconstruction of some of the implicit assumptions in these it might be a useful tool. Simply to make the argument that this is what a senior government advisor thinks should limit intrusive surveillance activity and allow us to ask if surveillance actors are even living up to that standard.