Once I was photographing a chunk of sandstone, with my crown graphic, at the far end of a public clothing optional beach. It was a cool and cloudy day - no sunbathers. 2 brave swimmers at the other end - much too far to tell whether they were suited or not. A fully clothed man approached and yelled at me, threatening " big trouble" for photographing at a nude beach. I offered a look through the ground glass (thinking he might have assumed a big camera was the same thing as a big telephoto lens), but he refused, and muttered angrily as he walked away.
I've photographed at that beach often, but not pointed my camera at anyone. No one else has seemed upset. I've seen lots of digicams and cell phone cameras there.
On a sunny day, I saw a family party, with an elaborate picnic, I'd have loved to photograph. The matriarch wore a sun hat and sandals. Her children and grandchildren (about 15 folks) were conventionally garbed in shorts, bathing suits, or summery dresses. Would have made an awesome picture, but I was too shy to ask and way too polite to grab a sneak shot. I've always regretted that I didn't ask.