9. The method of claim 1 wherein the act of associating the first user token with each user who is granted access to content items according to the first visibility policy is performed automatically.
9. The method of claim 1 wherein the act of associating the first user token with each user who is granted access to content items according to the first visibility policy is performed automatically. 11. The method of claim 9 wherein the maximum degree of separation is at least one and the act of associating the first user token with each user who is granted access to content items according to the first visibility policy comprises: accessing trust network data for the trust network to identify one or more users who are friends of the first user; and associating the first user token with each of the friends of the first user.