Aspects of the invention relate to sharing content stored on an object addressable storage (OAS) system among a plurality of users of the OAS system and authenticating users to an OAS system. In some embodiments, a user may store content units on the OAS system and control access by other users to these content units. In some embodiments, when a user grants one or more other users access to a content unit stored on the OAS system, the OAS system may send a notification of grant of access to the other user(s).