Plots and Paranoia: History of Political Espionage in Britain, 1790-1988 by Bernard Porter
The aim of this book is to describe the history of Britain's counter-subversive agencies and by placing them in their historical context, to assess their broader significance. It tells a story of spies, informers, political policemen, mail interceptors and phone-tappers. The book should be of interest to anyone concerned about present-day issues relating to Britain's secret state activities.