Years ago my girlfriend (now wife) called me and told me some drunk was
pounding on her door at 2 am and kept it up for a while before leaving and
she was scared to death. It was a VERY small apartment, 2nd floor, so
nowhere to run or escape. So I brought over one of my handguns and gave
her some instructions (she grew up hunting but didn't have much handgun
experience). She was concerned about needed to go to the range to
practice and my reply was "If someone breaks the glass and is reaching in
to unlock the door, just fire a shot into the drywall over the door. I
doubt they will stick around to see if your aim improves with the second
try".

Steve.

Chances are their underwear wouldn't improve either.