Under the 1977 Constitution of the Soviet Union, housing was guaranteed for every citizen and after Kazakhstan became a republic, a new housing code was established in 1992. From the 1980s onwards, many Kazakhs migrated to the largest city Almaty and squatted in shanty towns. In the 1990s, the Alma-Ata Union of the Homeless recommended to squatters that they should occupy unused land, summer homes or derelict buildings. When the authorities attempted to evict an informal settlement called Shanyrak in the mid-2000s there was a riot in which one police officer died; the poet Aron Atabek, who was chairman of Shanyrak's Land and Dwelling Committee, was arrested and imprisoned for 18 years. By 2016, estimates put the population of Shanyrak at 160,000 officially and at 220,000 when unregistered people were included.