Systems and techniques for mediating user communications. A user persona manager maintains one or more user profiles and manages user interactions with other parties and with service providers based on user preferences associated with the user profile or profiles selected for a particular interaction. The persona manager receives a single set of user authentication information to establish the user identity, and provides previously stored information to other parties and service providers as appropriate, and otherwise conducts user interactions involving communications initiated by or on behalf of the user. The persona manager also examines interactions initiated by others, selects user profiles appropriate to the interactions, and routes and responds to the interactions based on information stored in the user profiles.