A court does not take action on its own initiative. Challenges to the constitutionality of laws or court decisions that involved state surveillance measure have been brought before the Federal Constitutional Court primarily by means of constitutional complaints. The protection of fundamental rights as the protection of individual rights presupposes that a citizen can assert and substantiate that his or her fundamental rights were violated. However, surveillance measures normally take place in secret, and affected parties never learn about them, or if they do, only very belatedly.
As a result affected parties are essentially denied the opportunity to seek legal redress that is based on the allegation of a specific violation of rights. The Court addressed this difficulty by expanding the ability to seek legal recourse. In such cases, it admitted a constitutional complaint directly against a law authorizing surveillance. As a consequence, in contrast to other constitutional complaints, those seeking legal recourse are not required to challenge an action taken specifically against them. The fact that statutory authority provides for the possibility of potential interference with this individual suffices as the basis for the possibility of legal recourse.
(The judiciary and the surveillance state: general trends and German experiences în Judges as guardians of constitutionalism and human rights, ed. Elgar, 2016, la pp. 123-124)