8. The system of claim 6 , further comprising program instructions, stored on the computer-readable storage device for execution by the processor, to send a list identifying the set of candidate users to the querying user.
8. The system of claim 6 , further comprising program instructions, stored on the computer-readable storage device for execution by the processor, to send a list identifying the set of candidate users to the querying user. 9. The system of claim 8 , further comprising program instructions, stored on the computer-readable storage device for execution by the processor, to include on the list a reason as to why each candidate user was selected.