A stuck horn

I saw an unusual thing today that once I saw it, I had to wonder why I had never seen it happen more often. This electric bicycle rode down the street seeming to blow a shrill-sounding horn non-stop for no reason. "What is with the lady riding that yellow scooter?" I said to myself. This yellow scooter happened to be going the same way I was and I noticed that other people on the street were turning to look at the scooter blowing its horn - an unusual occurrence because the sound of horns blowing is ubiquitous here. When the yellow scooter came to a stop, I saw the driver turn off her ignition. She had a stuck horn. The first time I had ever seen that in China. How I haven't seen it more often now seems strange because Chinese drivers and cyclists use their horns more than their brakes or their turn signals.