American Asshole

So I'm walking to the UPS store, thinking that it's good to walk to the store and not always be driving. Immediately upon having this thought a car drives by, a guy leans out of the passenger seat window and gives me the finger, and yells out something ("asshole" or some such thing).

Now I've had this experience before but not in a long time. I actually associate it more with the east coast and the rampant stereotypical rudeness of suburban Long Island and New Jersey. I always thought it had something to do with the reduced status of pedestrians in an automobile-centered society.

I find myself asking, through what mechanism does this kind of thing happen? Is it supposed to be funny for the people in the car? The guy was sort of a beefy white beer-swilling frat boy type, not necessarily a local cowboy but maybe some idiot who got off the freeway to buy Cheese Doodles (it was near the entrance ramp to the 101).

If anyone has figured any of this out, please contact me.