was preferred for various reasons, including Muslim sensitivities that considered castes by definition Hindu, and preferred Tribes, a more generic term that included Muslims. The British colonial government, for instance, enacted the Criminal Tribes Act of 1871. This law declared that all those who belonged to certain castes were born with criminal tendencies. Ramnarayan Rawat, a professor of History and specialising in social exclusion in the Indian subcontinent, states that the criminal-by-birth castes under this Act included initially Ahirs, Gurjars and Jats, but its enforcement expanded by the late 19th century to include most Shudras and untouchables, such as Chamars, as well as Sannyasis and hill tribes. Castes suspected of rebelling against colonial laws and seeking self-rule for India, such as the previously ruling families Kallars and the Maravars in south India and non-loyal castes in north India such as Ahirs, Gurjars and Jats, were called "predatory and barbarian" and added to the criminal castes list. Some caste groups were targeted using the Criminal Tribes Act even when there were no reports of any violence or criminal activity, but where their forefathers were known to have rebelled against Mughal or British authorities, or these castes were demanding labour rights and disrupting colonial tax collecting authorities. The colonial government prepared a list of criminal castes, and all members registered in these castes by caste-census were restricted in terms of regions they could visit, move about in or people with whom they could socialise. In certain regions of colonial India, entire caste groups were presumed guilty by birth, arrested, children separated from their parents, and held in penal colonies or quarantined without conviction or due process. This practice became controversial, did not enjoy the support of all British colonial officials, and in a few cases this decades-long practice was reversed at the start of the 20th century with the proclamation that people "could not be incarcerated indefinitely on the presumption of [inherited] bad character". The criminal-by-birth laws against targeted castes was enforced until the mid-20th century, with an expansion of criminal castes list in west and south India through the 1900s to 1930s. Hundreds of Hindu communities were brought under the Criminal Tribes Act. By 1931, the colonial government included 237 criminal castes and tribes under the act in the Madras Presidency alone. While the notion of hereditary criminals conformed to orientalist stereotypes and the prevailing racial theories during the colonial era,