2. The method of claim 1 , wherein each of the digital signatures associated with the digital content items of the first group further includes a respective assertion made by the first agent that specifies a role of the first agent with respect to the associated digital content item of the first group, and wherein the reputation score for the first agent is further a function of the assertions.
3. The method of claim 2 , wherein the role is selected from the group consisting of author, editor, publisher, and reviewer.