Systems and methods are described that facilitate the management of contact information, at least some of the contact information related to entities in a serverless, peer-to-peer system. A contact store may store information regarding which other entities of a plurality of other entities are authorized to monitor presence of a user entity. Presence of an entity may generally indicate the willingness and/or ability of the entity to communicate and/or collaborate with other entities, for example. The contact store may also store information regarding which other entities of the plurality of other entities the presence of which should be monitored by the system. A user entity may be able to add contacts to and/or delete contacts from the contact store, for example. The user entity may also be able to modify the contact store to modify which other entities are authorized to monitor presence of the user entity and/or which other entities the presence information of which should be monitored by the system, for example.