All sorts of wierdos and fruitcakes hang around towns making a noise. Central london is full of clowns, acropbats, buskers and preachers. Hyde Park corner is pretty interesting too. I've seen the same in New York and all over Europe.
Those that want to watch or listen to their noise stop and toss coins into a hat. Those that aren't walk on by. To stop in front of any street entertainer and repeatedly tell them to shut up is rude.
For a little girl to be encouraged to behave like this is plain sad. The parents should teach her to stay away from strange men, not confront them. They must have been confident he was a nice enough guy to ignor her. He is seriously deluded in his beliefs but he handled it well; dare I say in a Christian way.
Just my take it, but then I live in the UK. Perhaps children like that are par for the course in the USA. Feel free to tell me to shut up - you must be over 18 to do so.