In particular embodiments, a computing device may receive authentication information provided by a temporary user and retrieve personal information associated with the temporary user from a server using the authentication information. The device may present a personalized user interface on a screen of the computing device for the temporary user, the personalized user interface being generated based on the personal information. The device may detect a terminating event that indicates access to the computing device by the temporary user is to be disabled. The terminating event may be detected by determining that a biometric information associated with the temporary user is undetectable, or determining that the computing device is put down. In response to the detected terminating event, information associated with the temporary user may be removed from the computing device, and the computing device may be reverted to a default state.