What's wrong with people?

The other day we were driving somewhere, and the craziest thing happened! We've drawn a little diagram to help you understand. We realize the numbers are small, but 1 is on the bottom and 4 is on the top.

The red X is us, waiting to turn left at a light. Along comes a car, the black square. He's driving along (#1), then all of a sudden, he goes into oncoming traffic (#2)!
He stops in the middle of the intersection, in front of oncoming traffic (#3), then pulls into the parking lot on the other side of the intersection (#4). He gets out of the car, walks to the sidewalk, raises both hands into the air and flips the bird toward traffic going in our direction. Then, with both arms still in the air, he yells something along the lines of "You want some?!" He goes back to his car, looks at the driver's side, then gets in and speeds off through the parking lot.

We just looked at each other and laughed. What else can you do?