Facebook has technology capable of recognising its users’ faces in photos. Now a patent suggests the social network could identify people’s cameras, to work out which device was used to take a picture.

Facebook says the technology could be used to suggest new friends and events, but also to identify fake accounts, for example. The patent, filed by the Californian company in January, suggests it could identify a camera based on physical characteristics, including lens scratches, to create a camera ‘fingerprint’.

It could then use that fingerprint to identify any picture taken by that camera and therefore a user that owns it. Combined with other pieces of information such as location data and facial recognition, which is used in the US but not in Europe, it could recognise photos taken by a user if they are uploaded to someone else’s account.

The patent says: ‘A camera signature comprises features extracted from images that characterize the camera used for capturing the image, for example, faulty pixel positions in the camera and metadata available in files storing the images.