As I was driving to get art supplies I saw a fellow who appeared to be about 30 riding a scooter. He was wearing shoes, shorts and a shirt. Soon I noticed he was immediately behind me. I could observe him closely using the rear view mirror. The traffic was stop and go. I already classified him as stupid since he had no protective riding gear. Soon I classified him as about to cause harm to himself and potentially others. He had ear buds in his ears. They were attached to an iPhone. He was frequently looking at his phone and texting while he was riding his motor scooter. The phone was in his lap so he was not looking at the road. I thought there was a high probability that he might rear end me. I moved into a left turn lane and he passed me at about 20 mph–staring down at his phone. I blasted my horn. He never looked up. Since that was last Monday, he may not still be alive.