: The privacy and data protection challenges posed by biometric systems have been discussed in detail in the last years. Both security opportunities and privacy risks however may develop and change with the technical enhancement of the respective systems, which also induces the emergence of new application scenarios. One group of such new scenarios appears to be the prevention of criminal or in other ways dangerous behaviour. From a legal point of view, this brings about new challenges which go well beyond the problems of authentication as such. While some of the features of the scenarios discussed below may not be feasible in the short term, it is apparent that the associated fundamental rights and data protection law problems will have to be addressed in the future. This applies to the international plane as well as to national legal orders, for which Germany will serve as an example in the following.1 1 Biometrics, behavioural Pattern Analysis and the Law From the very beginning of ...