1. A method comprising: storing user-specific data for each of multiple users on a mobile personal device, wherein the user-specific data is accessible through a persistence layer on the mobile personal device; associating the user-specific data for each of the multiple users with a user identifier for each of the multiple users; storing the user identifier for each of the users on the mobile personal device; receiving a request from one of the users having a first user identifier to operate an application of the mobile personal device, wherein the request includes access to the user-specific data associated with the first user identifier; intercepting the request and determining whether to process the request using an access controller; requesting the first user identifier responsive to the request to operate; comparing the first user identifier to the stored user identifiers; granting the request and enabling access to the user-specific data through the persistence layer if the first user identifier matches when compared against the stored user identifiers; and operating the application of the mobile personal device with the user-specific data corresponding to the first user identifier.