Alarm systems can stop home invasions when they are monitored well. In this video, burglars were trying to do a home invasion but were thwarted with a security system. There are two burglars here that didn’t know that they were on security cameras while they were robbing a lady’s house. Meanwhile, she was at work and saw the whole thing online. She was able to call police and get them out.
If you have a good security system with cameras in the home, then you can know when someone is there when they should not be. This is worth the cost I believe to protect yourself and your family. I review several DVR security systems on my site here. Just search for DVR in the top search box.