In 1988 Bhutan conducted a census in southern Bhutan to guard against illegal immigration, a constant threat in the south where borders with India is porous. Each family was required to present census workers with a tax receipt from the year 1958—no earlier, no later—or with a certificate of origin, which had to be obtained from one's place of birth, to prove that they were indeed Bhutanese citizens. Previously issued citizenship cards were no longer accepted as proof of citizenship. Alarmed by these measures, many began to protest for civil and cultural rights, and demanded a total change to be brought to the political system that existed since 1907. As protests and related violence swept across southern Bhutan, the government in turn increased its resistance. People present at protests were labeled "anti-national terrorists". After the demonstrations, the Bhutanese army and police began the task of identifying participants and supporters engaged in the violence against the state and people. They were arrested and held for months without trial. Soon the Bhutanese government arbitrarily reported that its census operations had detected the presence in southern Bhutan of over 100,000 "illegal immigrants" although this number is often debated. The census operations, thus, was used as a tool for the identification, eviction and banishment of dissidents who were involved in the uprising against the state. Military and other security forces were deployed for forceful deportations of between 80,000 - 100, 000 Lhotshampas accused of using widespread violence, torture, rape and killing. The evicted Lhotshampas became refugees in camps in southern Nepal. Since 2008, many Western countries, such as Canada, Norway, the United Kingdom, Australia, and the United States, have allowed resettlement of majority of the Lhotshampa refugees.