New statistical methods have been developed for the longer-term storage of microdata. These methods must comply, however, with the fundamental right to informational self-determination and the legal regulations imposed by the Federal Constitutional Court. Thus it is crucial to develop effective and coherent methods for protecting personal data collected for statistical purposes. Recent decisions by the Federal Constitutional Court are likely to result in the outlawing of comprehensive, permanent statistical compilations comprised of microdata from a wide range of sources and updated regularly. However, aside from such comprehensive methods, there are certainly other ways of using microdata that cannot be dismissed from the outset as violating constitutional legal norms. Internet access to statistical microdata is likely to take on increased importance for scientific research in the near future. Yet this would radically change the entire landscape of data protection: the vast amount of additional information now available on the Internet makes it almost impossible to judge whether individuals can be rendered identifiable. In view of this almost unlimited information, individual data can only be offered over the Internet if the absolute anonymity of the data can be guaranteed.
Keywords: Right to informational self-determination, census ruling of December 15, 1983, longer-term storage of microdata, primary statistics, secondary statistics, statistical confidentiality, absolute anonymisation, de facto anonymisation, additional information, pseudonymisation, personal data profiles.