Article: International reactions to Gaddafi's death were divided. U.S. President Barack Obama stated that it meant that "the shadow of tyranny over Libya has been lifted," while UK Prime Minister David Cameron stated that he was "proud" of his country's role in overthrowing "this brutal dictator". Contrastingly, former Cuban President Fidel Castro commented that in defying the rebels, Gaddafi would "enter history as one of the great figures of the Arab nations", while Venezuelan President Hugo Chávez described him as "a great fighter, a revolutionary and a martyr." Nelson Mandela expressed sadness at the news, praising Gaddafi for his anti-apartheid stance, remarking that he backed the African National Congress during "the darkest moments of our struggle". Gaddafi was mourned by many as a hero across Sub-Saharan Africa, for instance, a vigil was held by Muslims in Sierra Leone. The Daily Times of Nigeria stated that while undeniably a dictator, Gaddafi was the most benevolent in a region that only knew dictatorship, and that he was "a great man that looked out for his people and made them the envy of all of Africa." The Nigerian newspaper Leadership reported that while many Libyans and Africans would mourn Gaddafi, this would be ignored by western media and that as such it would take 50 years before historians decided whether he was "martyr or villain."

Now answer this question: Who said something about tyranny?
Barack Obama