what happens to a bicycle messenger when they don't obey the traffic laws, drive between the cars stopped at a light and the sidewalk on a busy road with no parking, right when a passenger is getting out of the car, getting doored in the process, usually at 20mph or so.
Since passengers don't expect a vehicle to be flying by between the curb and the car, they don't look.
"You see that dumbass get p-doored? He should either obey the traffic laws on that meat scooter or slow down. That's gotta hurt."