A server system comprising: a respective storage area for each of a plurality of respective parties including a first party and a second party, and a manager function for managing the storage. Each of at least some of the storage areas stores a primary instance of one or more data resources of the respective party. The manager function is configured so as, in response to the second party forming a relationship with one of the resources of the first party, to establish a secondary copy of that one of the resources of the first party in the respective storage area of the second party. In the secondary copy, the manager function also includes personal metadata describing one or more attributes of the relationship between the second party and the resource.