Wow, OP, I am with you.
Taking photos of my kids from several feet away is unpreventable, unobtrusive, and frankly not something I'm going to get bent out of shape about.
But chasing my kid while I actively try to stop the photographer while I'm yelling no? Yeah, put me in the throwing the camera off the cliff group.
Whether or not something is legal has nothing to do with whether or not something is morally acceptable, and dodging around a protesting mother to snap photos of a scared child is totally out of line. Would anyone here defend an American tourist's right to chase a scared insert-nationality-here child around to take a photo while their mother is saying, "No! No!" and trying to cover their child?
It's irrelevant whether the child in OP "should" be scared by being chased around by a complete stranger. The child WAS scared, and the mother was shouting NO. How is it ok to continue taking the kid's picture?
I think between this and the other thread... I'm ready for a hive break. Sheesh.