In one embodiment, receiving a notice from a first user associated with a first mobile device indicating that the first user wishes to share information of the first user with one or more second users respectively associated with one or more second mobile devices; accessing information known about one or more users and one or more mobile devices respectively associated with the one or more users; identifying at least one candidate for the first user based on the information known about the one or more users and the one or more mobile devices; and confirming one or more of the at least one candidate as the one or more second users.