What is wrong with people??

I was just driving home from the grocery store and was in the left turn lane at a red light. There was a man in front of me talking on his cell phone while he drove...illegally (for you non-Californians). When the left turn arrow turned green, the man was still on his cell phone looking down. I waited a few seconds and then gave my horn a light tap and when he looked up, gave a nice little wave - in my mind, letting him know I was just being polite to let him know the light hand changed. He, however, did not find it so helpful. He chose to drive into the middle of the intersection to turn, slow down until the light turned yellow, and then stuck his arm out of the window, fully extended, to make sure I saw then prompt middle finger he was throwing in my direction (still on the cell phone with the other hand). Then, he continued through the intersection, leaving me in front of the next red left turn signal to wait through another round of traffic.

Thanks jerk.

And so I ask....WHAT IS WRONG WITH PEOPLE???