Until the late 1970s, when military rulers deprived many citizens of their rights through detention without trial, physical assault, torture, harassment, and intimidation, the issue of human rights was not a major concern. The fact that Nigeria did not become a one-party state as most other African states did immediately after independence forestalled the emergence of repressive measures, such as the preventive detention acts prevalent in Africa. By the early 1970s, however, the days of "innocence" in relation to human rights were over.As Major General Yakubu Gowon's popularity declined, especially after he reneged on his promise to hand over power to civilians in 1976, criticisms of him and his cohorts increased. He reacted by detaining these critics for indefinite periods. This trend of abuse of the rights of regime opponents continued under the Muhammad/Obasanjo government and, after the creation of the Nigerian Security Organisation in 1976, human rights violations became frequent. The return of constitutional government in the Second Republic (1979-83) reduced the violations, although the human rights record was poor because of the increasing powers of the police force and the NSO and the constant harassment of political opponents. Under the Buhari regime military security was the criteria for judicial action, often in the form of military tribunals. The government not only gave the NSO greater powers but also promulgated decrees that directly violated human rights. The most notable were State Security (Detention of Persons) Decree Number 2 of 1984, which empowered the chief of staff at Supreme Headquarters to detain anyone suspected of being a security risk indefinitely without trial (detention was for three months initially, and then renewable), and Decree Number 4, which made the publication of any material considered embarrassing to any government official a punishable offense. Under Decree Number 2, many people considered "enemies" of the government were detained in NSO cells and allegedly tortured. Second Republic government officials, whom the Buhari regime held collectively responsible for the economic mess, were detained without trial or were tried by special military tribunals. At these tribunals, the accused was assumed guilty until proved innocent rather than innocent until proved guilty. Journalists and media organizations were regularly harassed by security agents; organized interest groups whose members dared to criticize the government openly or engage in demonstrations or strikes were proscribed.
Under the Buhari administration, the NSO engaged in widespread abuses of due process, including detention without charge and trial, arrests without pretext, and wiretapping. The NSO's performance was bluntly criticized after the 1980 uprisings by the Maitatsine movement. It had penetrated the movement but failed to prevent it from instigating bloody riots. The Maitatsine follow the teachings of Maitatsine Marwa, an Islamic leader from Cameroon whose activities in Nigeria led to his expulsion from Kano in 1960 and a series of bloody uprisings in the 1980's in which more than 4,000 persons are believed to have died.When Babangida toppled Buhari in August 1986, one of his main arguments was the need to restore civil liberties. The new regime prided itself on being a defender of human rights, and many of Babangida's initial acts justified his human rights posture. He released most of the politicians detained without trial and drastically reduced the jail terms of those already convicted. Fulfilling one of the promises made in his first national address as president, Babangida in June 1986 issued Decree Number 19, dissolving the NSO and restructuring Nigeria's security services into three separate organizations under the Office of the Co-ordinator of National Security. The new State Security Service (SSS) was responsible for intelligence within Nigeria, the National Intelligence Agency (NIA) for foreign intelligence and counterintelligence, and the Defence Intelligence Agency (DIA) for military-related intelligence outside and inside the country.