Recently i was asked to build a UserControl that uses the UserList of Community Server and randomizes the order of the items. I guess the best solution would be extending the QueryOverrides and provide a Randomizer QueryType. Sometimes this solution is not an option and you need a workaround. In this solution we ta into the PreRender event of the UserList and shuffle the datasource and call on databind. I do realize that calling DataBind in the prerender event of a control can cause serious problems but for the UserList this will not be the case.
Randomize Userlist for Telligent Community Server