Abstract: There is described a method of distributing rights-managed media data items to users, wherein each media data item has associated rights information, including a time-limited availability attribute. The method comprises, for each media data item: in a seeding phase; storing the media data item; receiving requests for the media data item from a plurality of users; determining the availability of the requested media data item based on the associated rights information; transmitting the requested media data item to the plurality of users: and storing information identifying the media data item, the associated rights information for the media data item and a list of users who have received the media data item.