1. A method comprising: processing a first composite image that includes an image of at least one unknown person to create a list of candidate persons, each candidate person having a predetermine relationship with one or more persons connected to the first composite image, the processing being based on a facial-recognition comparison of a face representation of the unknown person with face representations of the one or more persons connected to the first composite image; sending, to the client device of a first user, the list of candidate persons for display to the first user, each candidate person corresponding to a particular person identifier; and receiving, from the client device of the first user, a selection of one of the candidate persons for tagging the image of the unknown person with the particular person identifier corresponding to the selected candidate person.