I see home invasion stories all the time. Usually intruders just kick-in the door. In my opinion, the most effective and least expensive thing you can do to protect yourself is to add good door security hardware to your doors to make them as secure as possible. You can get what's called a Door Security Kit ( http://www.DoorSecurityKit.com ) which will stop door kick-ins. It's a long, thick metal plate that reinforces the door, the door frame, and the hinges.