The Rowlatt Act , also known as the Black Act , vested the Viceroy 's government with extraordinary powers to quell sedition by silencing the press , detaining political activists without trial , and arresting any individuals suspected of sedition or treason without a warrant . The Rowlatt Act , also known as the Black Act , vested the Viceroy 's government with extraordinary powers to quell sedition by silencing the press , detaining the political activists without trial , and arresting any individuals suspected of sedition or treason without a warrant .