An interesting concept poorly executed.
I'd have given a 1.5 out of 5 stars, had I been able to. The concept for the plot raises the score, but... Oh, so much 'but'.
The book felt like a draft rather than a finished publication. Each absurdly short chapter screamed 'soundbite generation' as if the author wouldn't give the reader anything longer than two or three pages so as to not overload the attention-span. The book was full of annoyingly intrusive spelling and capitalization mistakes, as well as oddly unnecessary tabs in a few places. It badly needed to be proofread before publication. (This might have fixed some continuity problems and inconsistencies in terminology too.)
Even after building backgrounds and motivations for some of the characters, I felt a complete lack of empathy or identification with any of them. They were shallow, and their behaviour was often implausible.
Possibly the greatest failure that prevented me from enjoying the book was the persistent evidence that very little research had been done; for example, the author showed no understanding of how the police and armed forces actually worked - a prime example of this was a scene involving a Special Constable (I won't mention further specifics so as to avoid it being a spoiler).
The story attempted a degree of cynicism that the author could not deliver, and for a story that was probably meant to be a thriller, it was far too predictable.