One of the things we have to deal with almost every day is the owner illegally allowing their dogs to run off leash and then yelling "It's OK" as the dog charges at us.
Last month on a trail near McCinnis Park a lady argued with us that it was OK for her dog to be off leash as she stood right next to a sign saying "All dogs must be on leash"!!
It's not just the legality, check out this awesome poster from the Alameda Animal Shelter.