This graph shows the origination of "Rumor" cases before the Special Court (Sondergericht) located in Darmstadt. The Special Court was charged with the prosecution of slanders against the National Socialist regime "Rumor Decree" of 21 March 1933. It suggests the regime's dependence on voluntary denunciation to isolate and neutralize independent-minded people in Nazi Germany.
Source: Harald Hirsch, "Politische Denunziation vor dem Sondergericht Darmstadt im Jahre 1935," in Friso Ross and Achim Landwehr, eds., Denunziation und Justiz: Historische Dimensionen eines sozialen Phänomens (Tübingen: edition diskord, 2000), 199-226.