The heavy U-lock used to lock the bike is used to do damage to a vehicle, like by taking off a mirror.
U-lock Justice is not legal justice, but it's the only justice some cyclists get for being hit by inconsiderate motorists.
U-lock Justice is the Bike Nazi term for it. Vandalism is the most common term used by normal people, including drivers, auto passengers, pedestrians, police and insurance agencies.
U-lock Justice is often dished out to drivers that the Bike Nazi feels is deserving, though many times it is applied to drivers who simply do not notice a cyclist because they're not riding safely or legally.
FRANK: "Why did he do that?"
ME: "Dont know, he was weaving in and out of traffic and I almost hit him."
FRANK:"Ahh, in their little bike world they call that U-Lock Justice."
ME: "Sounds like something a 13 year old made up. LOL"