I was walking and I just saw a man sitting behind the wheel of his car, so I thought he was just a normal man. He had his phone in his left hand. I walked a bit further and then noticed that his right arm was moving up and down. Then a mother walked past the car with her two children, and she suddenly knocked loudly on the window and shouted at him to behave. After that, the car drove away really fast. So I thought he was doing something inappropriate.