Signal processing keeps advancing with unexpected consequences. Roughly two years ago I posted a news from MIT where researchers showed how to "hear" a conversation in a sealed room by using a laser beam through a closed window to hit a chips package on the table in the room and by measuring the vibration of the package recreate the sound waves producing them.
Now NII, the National Institute of Informatics in Japan, has issued a warning to people that like to show the Victory sign when posing for a picture. Researchers at NII have shown that given the increased quality of cell phones cameras and the progress in signal processing the image of the fingertips can be used to extract the finger prints. At that point one could use a 3D printer to print a rubber sheet with those finger prints and pretend to be the other person in an authentication requiring finger prints. The photo can be taken as far as 3 meters away.
They also proposed a solution for those that absolutely need to have the V sign in their photos: use a titanium oxide transparent film to cover your fingertips. That would fool the detection of fingerprints in a photo but you would still be able to use your fingers, and their fingerprints for authentication.
In general the problem does not exist since most of these photos are published on social media that downsize the image and decrease to quality to a point where fingerprints are completely blurred. In some instances, though, you are given the option to download the full quality photo and that can be a problem.
It just shows that technology is a coin with two faces. Any advance brings good and somewhat unexpected undesired side effects.