Well, any criminal could break into your house just by busting a window. This is essentially the same, minus most of the noise and shattered glass. However, a burgular isn't going to rob a house that looks difficult to get into. They're obviously going to look around the block and look for the easiest house. So, its more important to make your house look more protected than it actually is. Simple lighting at night, not too many places to take cover (bushes, etc), as well as a sign that says: "beware of dogs" are really the only things you need to keep a burgular away.