5. A system according to claim 1 , further comprising: a time window module to determine a time window and to apply the query against the messages in the corpus that were created within the time window.
1. A system for identifying users relevant to a topic of interest, comprising: a query module to execute a query comprising one or more topics against a corpus of messages and to identify voting users associated with the messages matching the query; a candidate generator module to generate a set of candidate users comprising users connected to the voting users; a relevancy scorer module to compute a relevancy score for each candidate user in accordance with: 
 E[p|f u ,F u ]=( f u +α)/( F u +α+β) where E is an estimated probability p, f u , is a number of the voting users connected to the candidate user, F u is a total number of users comprising the voting users and non-voting users connected to the candidate user, and α and β are binomials; a candidate ranking module to rank the candidate users by their respective relevancy score; and a processor to execute the modules.