21. The computer readable memory device or storage device of claim 20 , wherein the computing further comprises computing the impact score from a power score indicating the power and an authority score indicating the authority.
21. The computer readable memory device or storage device of claim 20 , wherein the computing further comprises computing the impact score from a power score indicating the power and an authority score indicating the authority. 22. The computer readable memory device or storage device of claim 21 , the acts further comprising: computing the power score based on a number of other users that received at least one message from the individual user.