Schneier on CCTV

Truth is, I've always been a little surprised that CCTV surveillance hasn't caught on in America as much as it has in London. In our current atmosphere of paranoid self-righteousness, you'd think we'd have those cameras poised at every street corner.

In London, where they proliferate, they tell you that "it's the Irish"--i.e., that they came in as part of the campaign to quell independence terrorism emanating from Northern Ireland in the 70s. I've accepted that more or less uncritically (or incuriously). But comes now the world's best non-lunatic security blogger pointing out that the blinking things aren't really all that good (link). Bruce Schneier (for that is he) points to a number of studies that he says support his claim. Schneier elaborates:

Pervasive security cameras don't substantially reduce crime. There are exceptions, of course, and that's what gets the press. ... Overall, CCTV cameras aren't very effective. . . . They actually solve very few crimes, and their deterrent effect is minimal. . . . Most CCTV footage is never looked at until well after a crime is committed. When it is examined, it's very common for the viewers not to identify suspects. Lighting is bad and images are grainy, and criminals tend not to stare helpfully at the lens. Cameras break far too often. The best camera systems can still be thwarted by sunglasses or hats. Even when they afford quick identification -- think of the 2005 London transport bombers and the 9/11 terrorists -- police are often able to identify suspects without the cameras. Cameras afford a false sense of security, encouraging laziness when we need police to be vigilant.

Schneier concede that cameras probably are effective in reducing crime in enclosed areas with minimal foot traffic (think parking garages). And they do "move crime around." But this last point is equivocal: if Tesco gets crime out of Tesco, Tesco may be better off. But if crime merely moves next door, the overall crime rate is not affected.