Cameras also produce metadata. When I want to copy write photos I insert it into the metadata.
Cameras also can be used for facial recognition. Using photos posted online and through traffic, security, ATM and other cameras, it is possible to track your every move. All it takes is the application of sufficient computer resources, and the cost of those resouces is going down all the time.
Photos on FaceBook provide an increasingly useful method of analyzing connections, what with advances in facial recognition technology and the increasing resolution of photos. How many times this year have pictures been taken that include you in the background?