There will be those who see such snooping as a weapon of the morally supercilious and the politically censorious. They will, even though Locke doesn’t discuss this, cite instances where repressive states – Maoist China or post-war East Germany – have enjoined their citizens to spy on their neighbours with the goal of cracking down on dissenters. At the same time, civil society often encourages eavesdropping. “Careless talk costs lives” was the wartime slogan that one might rephrase as “Careful listening saves lives”. For good or for bad, local authorities across Britain increasingly outsource and technologise eavesdropping by allowing ratepayers to tell them where to place CCTV cameras.