I have, twice. Luckily didn't need to use it. First time I was taking my dog out to pee at around midnight several years ago, he saw a rabbit or something and was gone like a shot.
Wife gets in the car to go look for him, a car full of yutes parked at the entrance to our neighborhood up to no good sees a white woman alone and follows her out of the neighborhood and up and down the street for almost 2 miles. She didn't want to pull into our driveway but was scared shitless. So she calls me freaked out and I tell her come home, I'm waiting out in the driveway with my ar pistol, and I was ready to use it if they got stupid. They followed her up the street and she pulled into the driveway, they stopped on the street at the end of the driveway and just wait. After a few seconds of that I step out from behind my truck with my ar leveled at them, they got a good look at it and hauled ass. Just as they were leaving the cops entered the neighborhood (she had called them before me) and light the car up, all the occupants bail on foot. Dunno if they were ever caught, but there were cops driving around with spotlights all night.
Cops later said they were probably looking for people to to rob/carjack waiting like that in the middle of the night.
Second time was another car of yutes in another neighborhood after I'd moved, about a year ago. They were casing cars I guess. Anyway they decide to park between my and my neighbors house in the middle of the night, music blasting, neighbor goes out to ask them wtf they're doing, gets a pistol pointed at his chest for it. He backs off and goes inside, and calls me to warn me, (since they're outside my house) I had noticed the car but didn't see the gun. After his call I went outside around the back of my house, this time with my scorpion pistol and waited and watched them from the rear corner of my house where they couldn't see me. I had no idea if they were casing cars or preparing for home invasion robberies. I don't know wtf they were doing but they would have been in for a nasty surprise if they'd have started some shit. Cops were called and they bailed. Next night neighbors car was vandalized and then rammed about a week later in his driveway.
That's all I got. Kinda lame but scary as shit at the time in both cases. Both neighborhoods were pretty nice, quiet places, not in the ghetto.
What you guys got?