Two turns from my house, my car was aggressively followed by a menacing teenager. What situation have you been involved in that escalated quickly?

Moments ago I was driving into my poorly lit neighborhood after one of my head clearing drives. As I approached the stop sign before my street, I was startled to see that a car was parked right at the stop sign in front of me. I slammed on my breaks. As I pulled around the car, I said to myself "What the fuck is this?!" What I didn't realize was that there was someone sitting in the parked car, and both of our windows were down. So as I spoke he heard me. I turned, and he immediately began follow me, turning his brights on and driving very close. I passed the street that led to my house and turned the opposite direction. The car followed. I turned again and once again he followed. This went on for a few more turns, and I was growing increasingly alarmed. So I did the only thing I could think of. At the next stop sign I stopped and parked my car. He got closer and revved his engine. I motioned for him to pass. He revved again. Calling his bluff, I took my keys out of the ignition and shook them out the window, as if to say "This car is not going anywhere. Now what?" So after a few more futile attempts to intimidate me with engine noises, he backed away from my car and passed me.

After he was out of sight, I quickly made my way home. I decided to park backwards, with my bumper to the garage door, just in case he came through the street looking for me. Sure enough, as soon as I pulled my keys from the ignition the car came down my street. I sat in the darkness and watched him slowly pass by. Enough was enough. I called the sheriff. They are actively sending a patrol car to drive through my neighborhood. Right now I am sitting her in my dark living room with a samurai sword listening for strange noises and eyeballing my cat as she peacefully sleeps on my purse. As long as she doesn’t startle awake, I think I’m in the clear….

Reddit, what situations have you been involved in that have escalated quickly?