This thread reminded me of the time I had my tires punctured 13 years ago. I lived in a small town and thought my old bike was safe, locked outside, nearby my work place, a grocery store that closed around 11 P.M. (I caught an unexpected car-ride home with my wife and figured I would pick up the bike the next day). This town had (and still has) a very low crime rate (especially vandalism). I would still (to this day) feel confident parking my car over-night in this same area without harm. I was really surprised and disappointed when I found my bike with two flats (I could see cuts, like it was from a small pocket knife, and it looked like they had to put a bit of effort into actually getting to, and putting a hole in, the tube).
Anyway I figured it was bored kids walking around on a Friday night looking for something to do. I doubt that vandalizing a car in a similar way ever crossed their minds. I guess they figured they could get "away" with vandalizing a bicycle (as opposed to a more "important" object). I'm glad it didn't cross their mind to karate-kick the frame and rims (maybe they were too dumb or lazy to do the "job" right). I was able to boot my tires and patch my tubes (it was a cheap mid-eighties Huffy 35lb ten-speed, and I commuted about four miles both-ways a couple of times a week on it), so I wasn't out anything money-wise, it just made me a bit less trusting of "humanity" and was my personal introduction to a truly senseless crime.
As far as what I would do if I caught someone vandalizing my bike, I don't know. Pound them with my fists? That just doesn't seem like that would end up well. For one thing what if there is a significant age difference, I wouldn't want to be "that man" that beat that kid up. I suppose if you got the police involved and the vandal was actually inconvenienced for a few hours then maybe he might learn some kind of lesson. It seems like it would take an immature mind (in a kid) or an evil mind (in a adult) to consider puncturing a stranger's tires (rambling over).