Getting things thrown at you while cycling is not fun.
My son was cycling at over 30mph and all of a sudden something heavy hit him in the head and almost knocked him off his bike. He found out it was a water bottle thrown from a car that could have caused his death. My son rides sometimes over 60 mph coming down hills. Apparently it was some young kids thinking they were funny that threw the bottle at him as they drove by since he caught up with the car when traffic slowed. (This is when I wished I could carry a paint ball gun with me and fire off a few green permanent paint balls at the car ) That being said the driver was upset with the person that threw the bottle, we were just lucky Sheyn stayed the course.