For noncommercial use, just about any photograph created more than 75 years ago is now in the public domain and no longer subject to copyright restriction. So, say for example, I posted a photograph of my 2nd great grandfather, Elhanan Fitzgerald on his WikiTree profile. (Which I did.) He died in 1916, so the photograph is more than 75 years old. FamilySearch would then be within their rights to use this image without my consent, which they did. (I had absolutely no issue with them doing this... 100% okay.) However, say someone wanted to use pictures of my grandmother, Lucille (Krum) Remynse (1903-1999) from her profile. If they wanted to use the picture of her as a baby, the photograph would be more than 75 years old and there would be no problem. But if they wanted to use the picture of her as an adult with white hair taken in the 1960s, they would need my permission to use it. Which they would get if it was someone doing a family tree on another service.
Personally, I feel it is kind of uncool to use someone else's family photo without first trying to get their okay, even if it is old. But if the picture is of some public figure from more than 75 years ago, it is fair to use. Example - I was doing a profile of a person who had been a US congressman for a couple terms back in 1839-1842. I found a few photos of him from his time in congress and used one on his profile. Clearly public domain images and I did not need to worry about copyright restrictions. It is also nice if you can give credit to the photographer or the source from which you got the photo.
I am not a lawyer, so do not take any of this as legal advice.