Section 6 of the Justice and Security Act 2013 extended the use of the ‘closed material procedure’ (CMP) mechanism to any civil proceeding where certain conditions are met. The CMP is extremely controversial in itself and the general applicability authorized by the 2013 Act has been subject to significant academic criticism. However, comparatively little attention has been given in the literature to an extremely important factor: its application in practice by the courts. Five years after its initial passing, there now exists a significant yet understudied body of case law on section 6, and this article uses this to elucidate a general judicial approach to these matters. Matters of particular attention include the operation of the proscribed statutory criteria, the impact of human rights protections, and the wider roles of the judiciary and the legislature. In addition, this article highlights some unresolved tensions in the case law and sets out some implications for future cases.