Some of these exact techniques, but far more in-depth, have been used to track down and locate child predators who have uploaded images to the internet.
There was also this feet fetishist on reddit that could clear up that an image was clearly a fake since he already knew the feet in particular from another photo. He even got praise from the press for his specialist knowledge that was able to close the case. Don't know the details on the story and why it was important to determine an image fake or not, but I liked the ambivalent praise he got for his skills.
I believe this was in regards to Alexandria Ocasio-Cortez's feet.