Even though you realize your home is not an impregnable fortress you probably still put locks on your doors and windows. They won’t keep a determined intruder out but they should slow him down and/or force him to make some noise to break in. However, if you didn’t pay a premium for your locks then odds are they can be opened in seconds by even an unskilled child using a simple method known as bumping.
Granted, locks alone don’t secure a house, but they should at least put up a fight. If you are robbed and there is no sign of forced entry you will have a hard time getting an insurance payout.
Bump-resistant locks will cost at least $100 apiece. I bought a set of Medeco Maxum deadbolts here at that price.