How many CCTV cameras per person?

One of the factoids that’s been repeated again and again in the recent civil rights car crash is that there is at least one CCTV camera for every 14 people in the UK. This from the wikipedia page on CCTV

“The exact number of CCTV cameras in the UK is not known but a 2002 working paper by Michael McCahill and Clive Norris of UrbanEye[5], based on a small sample in Putney High Street, estimated the number of surveillance cameras in private premises in London is around 500,000 and the total number of cameras in the UK is around 4,200,000. The UK has one camera for every 14 people.”

Can we do better than this? We don’t have to limit ourselves to a “small sample in Putney High Street” – Has anyone created an interactive map where you can submit known public and private CCTV sites? I think it would show large areas that are not covered by CCTV and many areas that are completely over-saturated.

Would knowing a more accurate number change anything? Would knowing that there’s actually one camera for every 7 people mean that we had any more power to stop the things being put there in the first place? I’d be interested to see what the tipping point is before we get so fed up that we start using paintball guns on the High St like Bernard Cribbins facing a dalek.