Nacht und Nebel, meaning Night and Fog, also known as the Night and Fog Decree, was a directive issued by Adolf Hitler on 7 December 1941 targeting political activists and resistance "helpers" in the territories occupied by Nazi Germany during World War II, who were to be imprisoned, murdered, or made to disappear, while the family and the population remained uncertain as to the fate or whereabouts of the alleged offender against the Nazi occupation power. Wikipedia