If someone started taking pictures of my young son at waist level, without my permission, I would take a photo of him with my camera, then call the police explaining what I was seeing, then I would confront him ask him what he was doing. If I did not like the response I would hope my husband would take the camera off him and put it over his head. (Not in front of my child, I would take him for a walk).. If you're a professional/novice photographer and you are taking pictures of kids without permission you are walking a very fine line - people know not to do it! FFS!!!