Public beaches?

Recently, Terry and I had a fun weekend hosting the Campbell family on their first visit to California. Their older son, Matt, is our older daughter Lacy's boyfriend, and we had a lovely few days getting to know them and showing them around the Anaheim - LA area. On Saturday, we visited our favorite beach town of Laguna, taking in the Sawdust Festival, strolling Main Beach, and dining open air at the Cliffs. They took us up on our offer to do a California beach family portrait, so we brought along our camera, and found a relatively uncrowded spot of beach to take a few shots. One camera, one lens, no tripod, lights or flash equipment.

Within 2 minutes, a lifeguard came up asking for our permit. We explained that we were just taking pictures of our out-of-town friends, and he asked if this was a professional shoot. We said we weren't charging for the pictures, and again, they were friends from Missouri. He let us alone, and what we told him was true...but my frustration is this - since when does a family who wants a photo taken on a public beach need a permit if they'd like a pro to take it for them? I can understand if this was a private beach - trespassing in front of someone's home - or we were filming a movie with lights, reflectors, dozens of crew members etc - but this is a public beach, and there was no one inconvenienced by our presence. It's just not right to restrict public access to public beaches. As far as I know, this "permit only photography" is being enforced in Laguna and Newport Beach. How long before public beaches start charging the public to walk on the sand?