Under Glasnost the people were told a large amount about the horrors committed by the government when Stalin was in power. Glasnost gave new freedom to the people, such as freedom of speech, which was a radical change because control of ideas had previously been a central part of the Soviet system.
Thousands of political prisoners and many dissidents were released in the spirit of Glasnost. However, Gorbachev's original goal of using glasnost and perestroika to reform the Soviet Union proved futile and the government of the Soviet Union collapsed in 1991.
See also Perestroika.