Someone messing with your car
A scenario for you:
Let's say you've got a nice car. It's your new dream car, or it's a classic you've spent years sweating over restoring. Either way, it means a lot to you.
You're alone and leave a store into the parking lot to find someone messing up your car. They're keying it, breaking windows, or they're inside ripping the dash to shreds trying to get at the stereo. You're armed, have a cell, and they don't see you yet. You're at an angle where you can probably approach without being detected. Assume you're probably not a match for the guy physically.
What do you do?
As much as I'd like to administer a little justice here, I keep coming back to drawing as the wrong thing to do. I'm not a cop and not trained to hold people (until real cops arrive, assuming I could even call them while holding a BG at gunpoint), and I'm not necessarily ready to shoot (say he turns and starts walking away, I'm not shooting him in the back).
Yell "hey you" and scare him off from a distance and let him get away?
Sit back quietly and call the police while noting any details that may help?
Draw down and tell him to drop his ID and then run? What if he says he doesn't have any?