RCW 46.61.667 states: a person operating a moving motor vehicle while holding a wireless communications device to his or her ear is guilty of a traffic infraction. Last time I checked it's not illegal to honk your horn. They wouldn't install them in vehicles if it was. I don't get startled by car horns because I am aware of my surroundings. Unlike people on their cell phones who swerve in & out of lanes and endanger everyone arround them. In 2008, 6000 people died in distracted-driving-related vehicle crashes, & 500,000 were injured. I hope honking at people on their cell phones becomes a fad. So we can rid this epidemic once and for all.