In the US, basically any public place (nude beaches included) is open for people to film. I believe there are some exceptions like public restrooms, where there exists a "reasonable expectation of privacy."
But yes, people are also free to complain to the person and make them feel uncomfortable for the scumbag behavior.
In Europe (Slovenia) you can't film people without their consent even if in public, unless if there's a huge number of people. Thus you're filming the crowd and not just a select few.
And I'm pretty sure that even in European counties that theoretically require consent for publishing identifiable pictures of people in public, many thousands of such photos are posted every day.
There's the law and then there is etiquette. They do not necessarily match up. In this case the law is a lower limit, and you may face social counter-action: a person standing to block your camera, angry words, etc.
Still, free or not, I can approach the guy with the camera and complain, like OP did with the nudist beach creep.
I'm in Europe, not sure how this works to be honest.