Which Act was known as 'Black-Bill'?

The Rowlatt Act, passed in March 1919 by the Imperial Legislative Council, was vehemently opposed by Indian nationalist leaders and termed the 'Black Act' or 'Black-Bill'. The law authorized the colonial government to arrest and detain any person suspected of terrorist activities for up to two years without trial, denying the basic legal rights of No Dalil, No Vakil, No Appeal.