Two stories. Neither is especially violent.
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I was riding in a bike lane back in my first year of commuting, and saw some bonehead in a pickup truck pull out and completely block the bike lane as he was waiting for a break in traffic to turn left out of a parking lot (he was turning to go the other direction).
I got off my trusty steed, walked around the front of his pickup, and lightly hammered his truck's hood with my elbow as I passed.
As I got back on my bike to continue onwards, I heard him peel out behind me, and saw him swerve across both lanes of traffic to follow me, stopping in front of me with his truck angled across one lane and the bike lane. He got out of his truck and started pushing me, and kicked my bike. The guy was around twice my age and half my size (I was 6'3, 230 lbs at the time), so I asked him if he wanted to go, but he declined. I don't have the email handy that I sent to my buddies with the full details of the incident, but I believe that he said something about getting a bat from his vehicle. He eventually decided that he didn't want to take me on, and took off in his truck (now going the opposite direction of the way he originally wanted to go).
One friend of mine was watching from his office which overlooked the scene, and afterwards he told me that he saw the entire incident. "I wondered if it was you", he said. "I can't believe you didn't pound the guy into the ground when he kicked your bike". Good times, no damage to the bike.
--------------#2---------------------------
The second incident involved no violence, but it was fun. Here's what I sent around to other friends who ride. They still believe that I am nuts:
I'm looking to turn across Doyle Avenue into the alley behind the office. Fat Boy in a grey dodge minivan coming the other way comes to a complete stop in front of the Bike Shop cafe, and tries to (illegally and unsafely) wave me through. I shake my head, and wave him through, yelling "Get going".
Fat Boy then turns on his signal, and starts to turn into the parking lot across the road, behind Dawett (restaurant). He also rolls down his window to yell at me, but I pre-empt him, yelling, "I'm a car, treat me like one". While still parked in the middle of the road, Fat Boy yells back "You're not a f***ing car", and possibly something else.
As he turns into the alley that runs behind Dawett, I decide that I'm not going to take that kind of crap from a motorist. So I do a 180, cross Doyle, and start following him down the alley. He notices me following, and guns it. So do I. Fat Boy must have ended up doing 30-40 km/h, down a narrow alley, with cars on either side. I heard his tires lock and skid on the gravel as he drove over a big metal utility vault cover when he braked for the "T" corner at the end of the alley. He turned left at the "T", and headed towards St. Paul Street, blasting out of the alley onto St. Paul Street near the Bargain Mart. Lucky there were no pedestrians on the sidewalk, as there is zero visibility. I almost caught up to him just as he turned north onto St. Paul, and after carefully checking traffic, I continued chasing him down St. Paul. Fat Boy must have gunned it, because he turned left on Doyle (heading back in the direction from which he came in the first place, what a bonehead) and had driven out of sight by the time I got there.
I hope Fat Boy in the minivan filled his underwear with fear. I don't know why he was so afraid, but it was funny as anything. In fact, that was the most fun I've had on a bike this year. I wanna chase more cars, and intimidate more motorists.