CrAz3D is being a jerk in this thread, and I don't think he is a very thoughtful person, but he is somewhat right in the sense that this is not completely his fault. If you were to leave your car doors unlocked, with the key in the ignition, and someone stole your car, and was caught, he would held totally responsible in the eyes of the law. These measures we take to protect ourselves would be mostly useless if no-one were.out there consciously doing the wrong thing.
On the other hand, you could say "if I hadn't made it so easy for my car to be stolen, it likely wouldn't have been". So in that sense, you are partly responsible. But should you still lock the car? CrAz3Ds analogy about getting raped applies in this situation. Should a pretty girl really make herself ugly in order to avoid being raped? Of course everyone instinctively wants to say "no", but following the same line of reasoning we applied to the car situation, the answer could well be "yes". Like most choices, this is another optimization problem. Is the decreased chance of being raped worth sacrificing your appearance? Probably not. Is the decreased chance of having your car stolen worth the extra effort of making sure it is locked? Most likely.