> No amount of surveillance will 100% prevent any individual from being a victim of a crime.
No, but if it reduces crime by 99% would you be in favor of it? (See South Korea, Taiwan, Singapore.. examples of democratic countries with CCTVs all over the public space.. and before you say well those are racially homogenous countries.. I say look at Singapore. Singapore is very diverse racially, and yet they have very low rates of crime. This is because they have strict laws against crime and these laws are actually enforced)
EDIT: also, most crime happens at home, so if you really want a large reduction put cameras in everyone's home too.