The purpose of a privilege mechanism is to provide a means of granting specific users or processes the ability to perform security-relevant actions for as limited a time and under as restrictive a set of conditions as possible, while still permitting tasks properly authorized by the system administrator. For the administrative task of performing a system backup to be done correctly, all the files of the system must be readable. However one would not consider changing all the access control information for all the files on the system to be readable to accommodate performing backups. The solution would be to create a privilege that would allow a read override of the access control information allowing all the files on the system to be read for the backup procedure. This privilege would then only be used for specified tasks such as system backups. This exemplifies the basic security principle of least privilege.