Klass and others v. Germany, No. 5029/71, ECtHR (Plenary), 6 September 1978

Respect for private life. Surveillance powers and interference in private life for the protection of national security.

Art. 8 ECHR
Art. 13 ECHR
Art. 6 ECHR

As concerns the fixing of the conditions under which the system of surveillance is to be operated, the Court points out that the domestic legislature enjoys a certain discretion. It is certainly not for the Court to substitute for the assessment of the national authorities any other assessment of what might be the best policy in this field. Nevertheless, the Court stresses that this does not mean that the Contracting States enjoy an unlimited discretion to subject persons within their jurisdiction to secret surveillance. The Court, being aware of the danger such a law poses of undermining or even destroying democracy on the ground of defending it, affirms that the Contracting States may not, in the name of the struggle against espionage and terrorism, adopt whatever measures they deem appropriate. Whatever system of surveillance is adopted, there exist adequate and effective guarantees against abuse. This assessment has only a relative character: it depends on all the circumstances of the case, such as the nature, scope and duration of the possible measures, the grounds required for ordering such measures, the authorities competent to permit, carry out and supervise such measures, and the kind of remedy provided by the national law.