It was estimated that high, but using a flawed extrapolation from observations on just two streets in Putney: http://web.archive.org/web/20080704145855/http://

It was estimated that high, but using a flawed extrapolation from observations on just two streets in Putney: http://web.archive.org/web/20080704145855/http://www.channel4.com/news/articles/society/factcheck+how+many+cctv+cameras/2291167 http://web.archive.org/web/20080704145855/http://www.channel... I'd be interested to know the source of your (almost) certainty.