A camera does not prevent crime. It never has, anywhere on the planet. Monitoring does prevent crime, and people who look out for cameras aren't worried about the camera, they're worried about active monitoring. They're worried that the police will be there moments later. When you planned on breaking into a dozen cars to rummage through them in some vacant lot, the calculus is a lot different when there is a guy watching you.

Only everyone knows most of these cameras aren't monitored. The effect of the monitoring concern has dissolved.

And it's especially ridiculous to claim that cameras stop gang violence, which comes in ebbs and flows. Which was the "look it stopped all the murders!" There are various other absurd takes throughout this discussion, and HNers should realize that Flock has a massive PR campaign underway, and an enormous number of astroturfers spreading hilariously stupid stories about the gang members intimidated by...a camera.