Dogs can be very unpredictable as I experienced several months ago being bitten by a seemingly harmless pit bull mix in Ocean Beach Ca.
Several days ago I was in the same area in Ocean Beach Ca which is known to attract traveling young adults many whom have dogs. These travelers are from all over the country and many live in cars , trucks or vans with the dogs . The dogs are often off leash and many look neglected. The travelers and their dogs hang out on the beach seawall and they smoke , drink and use and sell drugs and generally are a nuisance  to local property owners.
As I walked the seawall a few days ago I approached this large group of adults and  several unruly  looking dogs. I slowed my pace and slid to one side of the sidewalk to avoid being to close to the dogs. As I did one of the disheveled young adults said " hey bud the dogs are friendly they won't bite" I said in response " yeah that's what every dog owner says" He told me to " piss off"

I walked past them and up a long flight of stairs to the top of the pier to get a few photos of the surf. As I was photographing the surf I heard a loud commotion with people screaming, cussing and yelling and 4-5 barking and yipping dogs. it seems a fight had broken out between the homeless young adults and the dogs were getting into the brawl. As the adults were squaring off with one another the large dogs were in a fighting biting frenzy......The dogs were jumping onto and biting both their owners and others who were involved in the multiple fights that broke out. Eventually the Police showed up and the fighting stopped. These large breed aggressive dogs can be a threat to bystanders if not controlled. I snapped these images from the pier as the fighting went on for several minutes.