If you are aware that your action are being watched, you will be more fearful of being caught and brought to justice for your crimes. Although there are some privacy concerns involved, security cameras are a major deterrent to criminals. They should be used more widely, both by private individuals and cities.
I believe the installations of closed circuit cameras around our cities help greatly to manage crime that was previously unsolvable. It adds eyes to law enforcement and when it is well used and maintained, it catches more robbers or vandal gangs that prowl during the night when there is not much activity going on.
Although I believe in privacy, I also want to be safe. If these cameras are catching the criminals then that's good. From what I understand Japan has always had a low crime rate. I think the technology in Japan has a lot to do with their low crime rate. They're more advanced.
Japan has been relatively a safe and peaceful country during the past couple of years, not necessarily because of technology, but more specifically because of Japanese ideologies and way of thinking. The Japanese way of life is greatly influenced by their conception of harmony as learnt through their traditional cultural practices including Zen.