The only time someone is gonna give away their spots is if they leave GPS coordinates in their pics, and most people have wisend up and donít do that any more.
Otherwise, if someone post a pic with enough background that you recognizes the spot, well that means you already scouted that spot, otherwise you would not recognize it. So you did not learn anything new, other than the poster shot ducks there, and more than likely he posted a limit of trash ducks so if that is your goldmine, well they have a saying for that.
Other than Rob Robertson, you wont see anyone posting a limit of mallards on public with pics that give away the spot. Well on second thought, there have been a few times, but not many.