Nope. The only way it's remotely useful in preventing crime is if someone is paying careful attention to the feed, and even if that's your only job it the human mind can only process so much data at one time, and CCTV operators typically have a fuck ton of other shit dumped on them because it's not a "Real" job. You can't really watch more than about 4-6 feeds tops without having to ignore some of them, let alone when you're taking calls, making logs and whatever else they want you to do to feel like they're getting their money's worth out of you. Source: was a CCTVs operator.

Just having a camera doesn't mean much if anything in crime prevention. Even if someone sees what's happening to you and immediately sends help your way, a lot can happen in the time it takes help to actually reach you.

Feeling secure and *being* secure are two different things and the former is actually a bad thing, since it robs you of the opportunity to realize you're at risk and be alert. Every time I hear someone whining about feeling safe, I want to slap them for that reason.