In the UK and Ireland the police "on the beat" are not armed. Because of the times we live in, we have to have special back up armed units that can arrive at an incident if necessary. The police themselves have always voted not to be armed, because they believe that there would be an escalation of incidences where guns were used.
I believe that CCTV is accepted and actually very popular over here. If there has been an incident like a robery, damage to a parked car, a fight, anything you can think of - the first reaction is "Did you check for CCTV" People will check with local banks, shops, filling stations etc. We have a "Crime Watch" program every few weeks where they show CCTV footage of roberies and many criminals are recognised and reported to the police. If you are law abiding you have nothing to fear.
Someone mentioned Hollywood a few days ago. I think that many Americans really believe that what they see in the movies is happening all over the Country, and this has them very jumpy.
You have a population of over 300m. Naturally some nasty things will happen - but most people will never come into contact with any of these crazies.