Mobile security techniques may protect information stored on a subscriber identity module (SIM) card as well as services that are accessible through the SIM card from unauthorized use. The techniques include receiving a service request to perform a security function at a server. The security function may affect a service provided to a mobile device by a telecommunication network, in which the mobile device obtains the service using a SIM card. The techniques further include performing the security function. The performance of the SIM function may be terminated in response to the server receiving a reversion command or an expiration of a predetermined time period.