The volume discusses the activities of the constitutional protection authorities in the tension between administrative efficiency and democratic oversight. The relationship between these two demands has indeed led to conflicts between supporters and opponents of constitutional protection from the very beginning of security policy. However, particularly due to highly security-relevant events, such as 9/11 and the NSU, constitutional protection is under intense scrutiny. This work provides an overview of both the general structures and processes of constitutional protection as well as current questions regarding the effectiveness and transparency of the constitutional protection agencies. Various reform perspectives are presented and discussed in a balanced manner.