Patent ID: 8302164

Claim:
A method comprising: receiving, by one or more computing devices, a request to transmit content relating to a first user to a second user, each of the users having a user identifier (ID); retrieving, by one or more of the computer devices, a black list maintained for the second user, the black list comprising a first set of user IDs of a first set users; accessing, by one or more of the computing devices, a graph structure defining relationships among a plurality of users, the graph structure comprising a plurality of nodes and connections between the nodes, each node corresponding to one of the users, each connection between two nodes being a single degree of separation between the two users corresponding to the two nodes; determining, by one or more of the computing devices, a gray list comprising a second set of user IDs of a second set of users based on the relationships defined by the graph structure, each of the users in the second set of users being separated in the graph structure from at least one of the users in the first set of users of the black list by only one degree of separation; and authorizing, by one or more of the computing devices, the transmission of the content to the second user if the nodes corresponding to the first and second users are connected to each other in the graph structure by a series of connections and nodes that does not comprise a node corresponding to a user in the second set of users of the gray list.