I have two dogs. Both are placid and good natured. But I am well aware that all dogs, mine included, have the potential to cause harm, if they become stressed and frightened by their environment.
I would never, never trust anyone else to walk my dogs - but that is a personal thing, and I know that some people's circumstances mean that they need help to ensure their dogs get enough exercise.
But entrusting your dog to a person who thinks it is OK to walk several dogs in a large group is not a good idea.
Dogs in a group will quickly try to form a pack, and the more dominant dogs will begin to vie for leadership. This causes stress amongst the group, so if any outside event occurs when the dogs are already stressed by the presence of so many others, an attack can occur.
This tragic event is not an isolated case. There have been many other incidents where multiple dogs have got out of control and caused harm.
So awful for the family of the woman who was killed, and for those passers by who had to witness what happened.