In the US, private property is probably one of the grayer areas. In practice, posting pictures from a private party is pretty normal--so long as no one says "please don't" which almost no one does in my experience. Obviously there are embarrassing/very private/etc. situations where it's pretty much inappropriate.
But in the US, shooting a casual photo of you in a public park for non-commercial (i.e. not marketing/advertising) purposes is pretty much fair game, especially if I'm not stalking you.
You go to the beach at Coney Island, New York and there’s NYPD notices listing about 50 things you’re not allowed to do on the beach. It’s a while since I was there so I might be misremembering some but in amongst things like BBQs, ball games, cycling and swimming when there’s no lifeguard I think maybe taking photos was one of them? I’m sure there’s good reasons why they’ve banned all these things due to people acting like anti social idiots on what must be a very crowded beach in the height of summer but I felt a lot less free on that beach than any other I had been to. Is that notice in violation of the constitution? I’m guessing the NYPD legal department has written this so probably not?
> Is that notice in violation of the constitution? I’m guessing the NYPD legal department has written this so probably not?
I wouldn't count on that. The NYPD was caught with signs that prohibited photography in the lobby of their police stations which violated the law. Someone actually had to take them to court before they'd change the policy and they still fought it.
In the US, private property isn't very grey. With a few exceptions like ag gag laws (which probably won't hold up to first amendment challenges) or invasion of privacy, you can photograph whatever you want on private property and the only recourse the person who controls that property has is to trespass you.
You mention one thing. Are they trespassing? It probably varies by state anyway, but a photo from public property is almost certainly OK perhaps absent big telephotos peering through windows--though, if you're a celebrity, leaving your shades open in probably on you I would guess.
But, yes, in general, a lot of things in this vein are OK in the US that at least theoretically aren't in some European countries.
I used "trespass" as a transitive verb. It's a remedy, not something the hypothetical photographer is doing. It's when a person who controls a property can demand you leave and not return under penalty of arrest. It's not linked to photography specifically—a person who controls a property can trespass you for virtually any reason or no reason at all. They can't make you delete your photos or anything else. The hypothetical photographer is only trespassing when they've been given notice that they need to leave (i.e. the person who controls the property has trespassed them) and they refuse to do so.
But in the US, shooting a casual photo of you in a public park for non-commercial (i.e. not marketing/advertising) purposes is pretty much fair game, especially if I'm not stalking you.