Every photo you click has a 'fingerprint' and Facebook could use that to identify you

Facebook has been identifying people from their faces in photos for long, but now the world's largest social networking service is taking user identification to another level.

According to a patent application filed with the US Patents and Trademarks Office, Facebook seeks to associate "cameras with users and objects in a social networking system."

The patent application says the technology would analyse images uploaded by Facebook users "to determine signatures of cameras used to capture the images."

Each individual camera (be it on a phone or a standalone camera) will be identified by its 'fingerprint' that will be present on every image taken by that camera and can even distinguish it from other cameras of the same make and model.

The camera signature or 'fingerprint' "comprises features extracted from images that characterise the camera used for capturing the image, for example, faulty pixel positions in the camera and metadata available in files storing the images."

Facebook will then connect the camera to specific users "based on actions relating users with the cameras, for example, users uploading images, users being tagged in images captured with a camera, and the like."

Facebook will also use this info to ascertain association between different users. For example if an image shot from your phone is posted by someone else to the social networking site, Facebook would know that there is a connection between you and the other person.

This technology, according to the patent filing, could also be used to identify multiple user accounts created by the same user and detecting fraudulent accounts.

Facebook says it will use this to recommend new friends, groups or events to users.

It is also possible that this technology can be used to identify any Facebook user from a random image downloaded from the Web.

However, this is still only a patent application and we do not know for sure if Facebook would actually add such abilities to its service but the privacy fears around such a technology are not unfounded.