I don't open the door; my front door has a peephole that I make judicious use of. I live in a "secure" building, where you theoretically need a key to get to the residential floors. If someone's knocking on my door, I check them out through the peephole with the gun in the bootleg position, then 99% of the time I don't open the door because it's usually a drunk who's lost and looking for Jenny or someone.