Blog post on verfassungsblog.de (and hiig.de) on the special investigator for the so-called NSA parliamentary investigation committee of the Bundestag (German parliament) The so-called NSA investigation committee of the Bundestag was established to investigate the legality of actions of the German government concerning the cooperation of German intelligence services with their US-American counterpart. Recently the committee requested to view lists containing selector expressions („Selektorenliste”), which for years the US intelligence services would give to the BND (German Federal Intelligence Service) to match them with their intelligence data. The German government refuses to comply arguing that the release of the data could lead to a serious risk to the public weal „Staatswohlgefährdung” as the US government threatened to cancel the bilateral intelligence services’ collaboration. Instead the German government suggested appointing a special investigator who could inspect the questionable information in the committee’s place. The blog post examines the legality of this proposal in light of the democratic principle of separation of power.