Active reserve (KGB) officers with a military rank who worked undercover in the Soviet Union. "Trusted contacts" were high placed civilians who collaborated with the KGB without signing any official working agreements, such as directors of personnel departments at various institutions, academics, deans, or writers and actors. Informers were citizens secretly recruited by the KGB, sometimes using forceful recruitment methods, such as blackmail. The precise number of people from various categories remains unknown, but one of the estimates was 11 million "informers" in the Soviet Union, or one out of every eighteen adult citizens The active reserve was established by Yuri Andropov in
KGB victim memorials KGB victim memorials Memorials to victims of the KGB have been set up in several countries that were formerly occupied by the Soviet Union, often in former KGB prisons, to document the repressions of the Soviet secret police and to commemorate its victims. Some are in the form of monuments at the location of KGB prisons or execution sites, others are museums and documentation centres. The KGB Cells Museum in Tartu is situated in the "gray house", which in the 1940s-1950s housed the South Estonian Centre of the NKVD/KGB. The basement floor with the cells for prisoners is open for