As with other manners of mass surveillance, there is a defensible argument for the massive deployment of this technology. Many crimes have been solved every year on the basis of the identification of suspects through CCTV footage. In many cases, even the crimes themselves are captured for posterity - providing concrete evidence for a series of events that would otherwise be a contradictory jumble of half-remembered eyewitness testimony.
But there is also a counter-argument that says that none of us has ever tacitly agreed to being filmed anonymously as we go about our business. As with the adoption of fingerprinting in schools, it is a slow normalisation of the idea that we should expect to be filmed every day of our lives - our movements captured.
And despite the claims made on behalf of CCTV, it remains surprisingly limited in utility - as shown in recent high profile cases such as the London Bombings, the death of Ian Tomlinson and the 'plebgate' affair. Even when events are recorded on camera, they must be interpreted through fallible human eyes and as such can hide as much as they reveal. During the inquest into the 7/7 bombings, for instance, barely any CCTV footage of the bombers has been released into the public domain - despite forming the backbone of the official narrative of events.
By some estimates, there are between 4.1 and 5.9 million CCTV cameras in operation in the UK today. Of those just 70,000 are said to be accountable - i.e., belonging to public authorities. The rest are in private hands, their usage unknown.