Lonewolf sums it up accurately, but I would like to emphasize his last point, #7: Packing is no excuse to be sloppy. Getting into a situation where a confrontation is probable is just stupid, and a firearm is not likely to get you out of it unscathed. They really are a last resort and a desperate one at that. To succeed, you need total situational awareness. If you have that, you are less likely to get into a shooting scrape to begin with.