No, I do not need permission to photograph in a public place

From Journal of a Photographer:

That made this lady furious and she said “I will call the cops now” and took out her cell phone. It was a bizarre situation and the only think I could say in that moment was “Alright, go ahead and call the police. Then we can speak about that again.” She looked a little confused, I guess she wasn’t expecting such an answer. She didn’t call the cops but went over to one of the workers in the amusement park telling him that I photographed his son, that I refuse to delete the images and that he should call the security. Nick and me were just looking at each other finding this situation more and more obscure.
Here.