Abstract

In German police law the traditional legal threshold for imposing security measures was the existence of a “concrete danger”. The police could only intervene if it they could demonstrate the likelihood that a given situation would lead to a damage of legally-protected rights or institutions. Starting in the 1990s and reinforced by a number of new security regulations after 9/11, the focus on national security in German administrative law has shifted away from this traditional approach and toward a more pre-emptive approach. An increasing number of precautionary measures, using new information-gathering techniques and devices, have been introduced to facilitate data mining and processing. Many traditional legal standards are in danger of being undermined by the increasing predominance of the precautionary principle. The principle of proportionality, for example, is at risk of losing its grip if the mining of certain personal data is set in relation to the prevention of massive terrorist attacks. In a remarkable series of decisions, the German Federal Constitutional Court has struck down laws and administrative measures of the police and secret service agencies which placed too much emphasis on the precautionary principle. Besides requiring procedural safeguards, the Court has insisted on material standards for achieving an appropriate balance among the relevant thresholds for imposing a security measure, the intensity of the intrusion into fundamental rights and the security interests at stake. The scaling of the intensity of various intrusions and the scaling of various security interests do not pose significant problems. However, the process of establishing thresholds involving various types of judgments concerning the probability of damage, such as general threat levels, different forms of danger assessments, and risks, is not yet well understood. This article analyzes various thresholds in the light of theories of probability to establish a system of thresholds which will comport with the constitutional requirements that have emerged from recent decisions of the Federal Constitutional Court.