1. A computer-implemented method comprising: receiving a request from an additional user of the social networking system to present a content item to a user via the social networking system; determining whether the additional user is an authorized user to present one or more content items to the user based on information associated with the user by the social networking system; responsive to determining the additional user is not an authorized user, withholding presentation of the content item to the user; generating a pending message interface identifying the additional user and a request to identify the additional user as an authorized user; and communicating the generated pending message interface to a client device for presentation to the user.