Use Case#2 - Sharing private photos scenario


Sue has uploaded her photos on a photo sharing appliction and publishes them. She uses a certain privacy policy which ensures that only her friends can see her pictures. Alice, a friend of Sue, logs in to the social photo sharing site and sees the photos of Sue. Alice decides to republish some of Sue's pictures on her blog. Alice is not allowed to do that because Sue gave her friends only usage rights but no reuse rights. When Alice marks the pictures and clicks the republish button the republishing tool informs her that she is not allowed to do that, but can ask Sue for permissions.

Alice asks Sue via email if she can republish a certain picture on her blog and Sue decides that she trusts Alice. Therefore Sue extends the set of policies protecting her photos. Now all friends of Sue have usage rights and Alice in addition has reuse rights. That means Alice is allowed to modify, republish, annotate and aggregate all pictures of Sue.

Key license conditions:

  • Usage Permission: play, display
  • User Constraints: only confirmed friends (i.e. bidirectional confirmed friends)
  • Reuse Permissions: modify, excerpt, annotate, aggregate
  • User Constraints: only Alice