Smile to pay. Customer recognition. Airport screening. These are some of the functionalities that face recognition brings to camera surveillance nowadays.
It will also allow for tracking people, building sociograms, can be integrated with different databases, behavioral analytics, and mass surveillance networks.
Soon also in Sweden, by the Police: https://integritetsnytt.wordpress.com/2017/02/13/sverige-polisstat-om-5-4-3/ (in Swedish)