1. A method comprising: by a computing device, accessing a social-networking information item and a media file associated with a first user, wherein attributes of the social-networking information item comprise a list identifying one or more second users associated with the social-networking information item; by the computing device, determining based on a facial-recognition algorithm a matching score of each of one or more of the second users to each of one or more faces in the media file; by the computing device, for each of the second users with a matching score above a threshold value to a face in the media file: comparing first spatio-temporal information of the media file with second spatio-temporal information of the second user; and adjusting the matching score of the second user to the face based on the comparison; by the computing device, determining one or more potential matches between the second users and the faces in the media file based on the adjusted matching scores; and by the computing device, tagging the media file with information identifying the social-networking information item based on one or more of the potential matches between the second users and the faces in the media file.