Mobile communication offers many new opportunities. However, because of the mobility of the subscribers trustworthiness of data, reliability and security are major issues. Our objective is to increase the network's trustworthiness by providing means to prevent generation of moving tracks: The protection should be shifted into a subscriber`s domain where the administration of the location information of his mobile station is handled as far as possible. Outside his domain, the subscriber should be able to act anonymously whenever possible. The location management strategies presented in this paper achieve anonymity of the communicating parties and therefore fulfill the requirement of privacy. Keywords Security, Privacy, GSM, Data protection, Anonymity, Pseudonymity