The present invention is directed to technology for determining the set of groups of which a user is a member. A user can be a static member, dynamic member or nested member of a group. A user is a nested member of a first group if that user is a member of a second group and the second group is a member...http://www.google.se/patents/US7673047?utm_source=gb-gplus-sharePatent US7673047 - Determining a user's groups
