Yeah, bullets don't always stop in people. Got to pay attention to where your bullet is going to end up. More people should be informed of over-penetration though. I am sure most people would use common sense to deduce the fact that it could happen, but they probably wouldn't think of it until pointed out. However, they will still probably not think about it after adrenaline takes over and they start firing. This is one of the many reasons people need to practice with their firearms a lot. So that they will become more comfortable with using them. It may relieve some of the stress in an emergency situation, possibly enabling you to think clearly before using it, even if you only have a split second to access the situation.