The text elaborates on the role of Argentinean human rights organization Mothers of the Plaza de Mayo in constructing social memory and in imparting information about crimes of state terrorism and military dictatorship in Argentina in 1976-1983. Assuming that the memory about disappeared victims of military dictatorship and about crimes of state terrorism is the basis for constructing principles and activities of social movement of Mothers of the Plaza de Mayo (Las Madres de Plaza de Mayo), it was acknowledged that presenting the subject matter would require defining the concept of social memory, revealing functions of the past in the present and explaining the historical context of state terrorism in Argentina. The article will also discuss various elements of the concept of social memory, socio-cultural mechanisms of generating and supporting social memory, as well as the influence of the memory of the past on the collective identity. The pressure on institutionalized forgetting about events of the painful past will further be developed. The authoress also describes the activism and articulation of human rights activists - Mothers of the Plaza de Mayo and four main areas of their activity: space, body, networks/information, motherhood. .