We have had this debate many, many times. It is a very complex question the answer to which varies greatly from city to city and state to state. There is no simple easy answer. It varies by local and state law as well as personal moral guidance. What one person would do is not what someone else would do. It is critical that one knows the laws of their state when it comes to using a firearm in defense of themselves or others.
In short, it is far too complex a matter for easy answers and has, in the past, led to really nasty exchanges not fitting for THR.
