I want to make it clear that my opinion that urban dogs need to be leashed is not that of a dog hater. Here are the views of the ASPCA and the Humane Society. Both organizations are dedicated to the protection of animals:
Click to read Urban Dog Etiquette & Street Sense
Click to read their NYC page
The Humane Society -
Click to read "Are You a Responsible Pet Owner?"
Click to read "Caring for Your Dog: The Top Ten Essentials"