The British Military is alleged by author Tony Geraghty to have exploited a number of information sources during security operations in Northern Ireland. Geraghty describes these in his book, The Irish War, basing his description on an extract from an unspecified, classified document passed to him by an unspecified informant, later identified as a former Army Officer, Nigel Wylde. Geraghty claimed significant capabilities for these systems and extensive use by both British Military Intelligence and Police.