Using Freedom of Information requests, we asked almost 100 local authorities in the UK how many CCTV cameras they operate.
Both the Shetland Islands Council (101) and Corby Borough Council (90) - among the smallest local authorities in the UK - have more CCTV cameras than the San Francisco Police Department (71).
Eight British cities have more CCTV cameras than the authorities in Paris.
The London borough of Wandsworth has as many CCTV cameras (1,113) as Dublin City Council, the Police departments of Johannesburg and Boston and the City of Sydney authority combined.
Watch Michael Buchanan's CCTV investigation in full on Newsnight on Monday, 20 July 2009 at 2230 BST on BBC Two.