The kingdom has a history of banning religious proselytizing, which critics denounce as a violation of freedom of religion and a policy of ethnic cleansing. Starting in the 1980s, Bhutan adopted a policy of "One Nation One People" to exert cultural (in language, dress and religion) and political dominance of the majority Drukpa people. The policy manifested in banning of teaching of Nepali language in schools and denial of citizenship to those who were not able to prove officially issued land holding title prior to 1950 specifically targeting Lhotshampa representing one-third of the population at the time. This resulted in widespread unrest and political demonstrations. In 1988, the Bhutanese authorities carried out a special census in southern Bhutan, region of high Lhotshampa population, resulting in mass denationalization of Lhotshampas, followed by forcible deportation of 107,000 Lhotshampas, approximately one-sixth of the total population at the time. Those who had been granted citizenship by the 1958 Nationality Law were stripped of their citizenship. Members of Bhutanese police and army were involved in burning of Lhotshampa houses, land confiscation and other widespread human rights abuses including arrest, torture and rape of Lhotshampas involved in political protests. Following forcible deportation from Bhutan, Lhotshampas spent almost two decades in refugee camps in Nepal and were resettled in various western countries such as the United States between 2007 and 2012.