Crimes happen when the risk is lower than the reward. A camera increases the risk so changes the balance.

If a criminal chooses to not commit a crime (or commits it elsewhere) because the risk/reward balance is changed, then it prevented the crime from happening (there), and made that location safer.

So there is no doubt that the cameras make places safer. Even fake cameras can make a location safer. The question is whether the cost to personal integrity makes it worth it. Most importantly: who answers that question, and who ensures the cameras aren't used for bad purposes? That's probably a smaller problem in London than in Beijing.

Answer: daily double! (Just kidding.)

Why not make cameras that output only encrypted video which may be stored by agencies and decrypted only when people holding the right keys come together during a trial or active police investigation? That would be strictly better for privacy than what we have now - which is total surveillance.

Brookhaven is just north of Atlanta and when I lived there they implemented license plate cameras. They would scan for stolen cars and alert police. The police recovered more cars in the first month than the prior year combined.

The companies are now selling to private communities. [1]

[1]https://www.google.com/amp/s/www.ajc.com/news/local/meet-the...

That depends, having cameras up around your house certainly makes it a less appealing target than your neighbor who doesn't have cameras. Other than those sorts of situations though, yeah.