One of the most dangerous dogs I ever met was a standard bred poodle - high strung raised as a "show" dog by someone who really didn't understand dogs and left its care to others. Would snap at anything that came into its space. Owner not dog.
I understand where you are coming from Catherine - you have heard that sharks are dangerous, have read that sharks have attacked humans so you have decided to avoid them and protect your children from them notwithstanding information that tells you that almost all sharks are benign. A rational choice given limited information. One made by much of the world.
With more information a more rational response might be to avoid the "West End" and particularly places where idiots hang out and have large dogs free in a yard.
However, given the difficulty in identifying who exactly owns a dog it is also rational to avoid any type of dog that is prone to being owned by the idiots out there who create vicous dogs unless you know the owner. Not my choice, but I am a little more careful when around the type of dogs that these idiots might own and I don't know who owns the dog. If I see a "pit bull" off leash and don't know the owner my radar goes up and I will not turn my back on the dog. This used to apply to dobermans, and before that german shepards, but idiots have switched so I no longer worry about them.
Would not go so far as to avoid the breed altogether even if I know the owner because I know that the owner has far more to do with temperment than breed. That is my choice however.
(Found the "pit bull" on the second try. Interesting pictures - somewhat misleading, but only slightly.)