The Mothers of the Plaza de Mayo were upset because their children were missing, leading to a movement that highlighted human rights abuses in Argentina.
The Mothers of the Plaza de Mayo were upset with Argentina's military government because their children were missing. The Argentine military was responsible for the forced disappearance of thousands of individuals, including young people, during the country's dictatorship.
These mothers, wearing white headscarves, protested in front of the presidential palace, demanding information about their missing children. This movement brought international attention to the human rights abuses in Argentina during this period.