Rowlatt Act of 1919 named after British judge Sir Sidney Rowlatt effectively.
Its provisions were
1. It gave British imperial authorities power to deal with revolutionary activities.
2..By this act, the British severely clamped the rights of Indians. Hence, they opposed this Act.
3. The Act authorized the government to imprison for a maximum period of two years, without trial, any person suspected of terrorism living in the Raj.
The Indians opposed it because their rights and freedoms were curtailed and they find it difficult to move freely.
Mahatma Gandhi opposed the Act by organising strikes, rallies, processions etc. He wanted Civil Disobedience Movement against such unjust laws.