17. A non-transitory computer-readable medium having computer-executable instructions that, when executed, cause a processor to: manage a plurality of user identities of an individual user, the plurality of user identities pertaining to the individual user and describing different sets of personal information of the individual user, and to select one or more of the user identities of the user that satisfy a set of identity requirements of a security policy obtained from the environment; evaluate one or more privacy preferences of the one or more selected user identities of the user against a privacy policy obtained from the environment to determine which of the selected user identities satisfy the at least one privacy preference; and process, by a policy editor, a privacy policy from the environment, generate a reduced version thereof, and supply the reduced privacy policy as the privacy policy used by the privacy engine evaluation.
18. The non-transitory computer-readable medium of claim 17 , wherein the instructions further cause the processor to: receive from the environment a security policy having requirements; process the security policy to determine whether any of the user identities satisfies the security policy requirements; and cause the evaluation operation to use the privacy preference of any user identity determined to satisfy the security policy requirements.