I am leaving on a road trip to San Diego on monday or tuesday. I thought while driving that when it came time to eat I would stop at places, if possible, where people eat outside so I could take photos. I am fairly new to photography and would like to know the protocol for taking pictures of strangers. I have only done that once and I asked permission. Do I need to ask permission of every stranger? What is the proper procedure? Any help would be greatly appreciated.

Betty