Personal safety is the #1 priority. I don't understand why folks don't seem to understand that. A door lock is probably free (already on the door) and takes 1 second. And can literally save your life. In fact, it's more than just saving your life (or the lives of loved ones), because the TYPE of torture or violence or death imposed upon you as a home-invasion victim would be at minimal psychologically very harmful; and worse, it's not uncommon to be beaten, raped or gang raped, or murdered very brutally (beat to death, stabbed to death, driven somewhere and held hostage, burned alive, etc.).
One of the absolute worst examples was in CT. If you aren't aware of this you should be. In short, two convicts followed a pretty mom and one or both daughters home to their upscale house. They waited for an opportunity and snuck in at night through an unlocked window. They found the dad asleep on the couch and beat him to death (they thought he was dead). Then they raped the 3 females. They took mom to get $15000 from the bank. They returned. The father had survived and crawled to a neighbors for help. Meanwhile, after raping some/all of the 3 females, while they were presumably still alive, the 2 cons set the house afire and burned them alive. The two stole the family car in their escape, but were quickly caught, prosecuted and convicted for murder, rapes, arson, kidnapping, etc. and are serving life in prison (death penalties commuted to life w/out parole).
All because of an unlocked door or window (and no other security like a dog) - and probably compounded by nobody having a self defense weapon readily available.
http://www.cnn.com/2010/CRIME/10/05/che ... on_murdersLocked doors are obviously a no-brainer. If you're not smart enough to lock your dam* door, well then I guess you failed at life. Who is so naive to think they don't have to lock their doors? I've had to drive this point home to a few people, who probably never even considered how critical it is.
A door lock is easy to defeat, of course, but it's a start of layered security. It keeps honest people out, and criminals have to force his/her way in. That does a few things:
* Noise - alerting homeowner or witnesses or dogs
* Trail of evidence of forced entry, supporting any self defense claim. Just watched a vid yesterday of a man with a machete attempting a forced entry. Even a flimsy door required about 3 good kicks before the attacker gained entry. That required a lot of noise and energy, and the home-owner was shouting (you could hear on film) that he had a gun and would use it. Sure enough, after mr. machete kicked his way in he was dropped by the homeowner.
* Forensics (glass particles, blood from injury, shoe prints, etc.)
* Injury to burglar possible
I have layers of security, and have a gun at arms reach in every room or on my person at all times, cameras, dogs, multiple locks, windows and doors braced, etc.