Police officers, medics and firefighters do not break into law abiding homes through locked doors, without announcing themselves. You can not know an unknown individuals intent. Fortunately our laws have been put in place to recognize this. Firearms are not intended to be "warning" devises. Would politely suggest those that think they are, should consider investing in some non lethal alternative.

You can not tell if someone is armed by looking at them, and if they are close enough to see in a house, they are close enough to attack, while you are attempting to discriminate their intent.

Nothing indiscriminate about it, it is directed at people willing to break into your home without caring whether you are home or not. This action in and of itself indicates they are a danger.