This is the kind of insensitive attitude that annoys me - 'ah shure he's only playing' as a child screams his head off in fright.
The point is that some people are afraid of dogs and, as truthseeker said, some dogs are unpredictable which is why, presumably, there are laws and regulations regarding where they can and cannot be let off the leash. My nephew started screaming the minute the dog bounded up at him (he was nearly as big as my nephew) and was not picking up on my terror. Even if he was, why does this excuse the adult who owned the dog failing to deal with the situation or to apologise for any upset he had caused, particularly as he was the one in the wrong and it was a little 4 yr old who was distressed. I got an email back from Dublin City Council who have confirmed that, after 11am, dogs must be on a lead everywhere in the park. Presumably this particular moron decided to ignore that.
As we were walking back home along the river path a girl passed us holding her dog by the actual collar. She laughed when she saw me looking and said 'I have to hold him like this. He loves children and is inclined to jump up at them'. That is the kind of common sense attitude that all dog owners should have not the stupid 'don't worry, he won't hurt you. He just likes jumping all over strangers and enjoying himself'.