I rarely get hoots from drivers but it happens. I used to flip them the bird but I have stopped. As others said, responding in kind may just wind them up more against the next rider. Even worse, you may enrage a total nut job who will turn the truck around and run you off the road or do an Easy Rider. On DC news yesterday and today everybody is upset about a surveillance video that shows a 69 YO man getting beat down by a 20 something on the Metro escalator. The story says the kid shoved the guy exiting the train door or something, words were exchanged and bam. You can clearly see that the kid is moving away up the escalator when the old guy makes some angry comment. The kid then turns back and spits in his face at which point the old guy sort of jabs back or pushes him away. The kid then starts punching him. The kid may or may not have started the incident but the older guy would have been better served holding his tongue. Gotta admit it can be hard to hold back when somebody f's with you, but...