15. An computer program product as in claim 14 , wherein producing the generation score includes: for each fact of the set of facts: matching an attribute of the fact to an attribute of a predetermined set of attributes, and assigning a fact score to the fact based on the attribute; and combining fact scores assigned to facts of the set of facts.
14. A computer program product having a non-transitory, computer-readable storage medium which stores code to perform KBA, the code including instructions to: obtain a set of user facts from a personal information management (PIM) server that is under the control of an organization, each user fact of the set of user facts including a reference to a user identifier of a user that is a member of the organization; generate a set of KBA questions from the set of user facts; and provide selected KBA questions of the set of KBA questions to a person that has submitted a request to access resources of the organization, the request including the user identifier; wherein generating the set of KBA questions from the set of user facts includes: for each KBA question of the set of KBA questions: producing a generation score that is based on the facts of the set of facts from which the KBA question was generated, removing the KBA question from the set of KBA questions when the generation score is less than a threshold generation score, and keeping the KBA question in the set of KBA questions when the generation score is greater than the threshold generation score.