Who described the Rowlatt Act as a black act?

The Rowlatt Act was described as Black Act by Indians. This act led to Rowlatt Satyagraha. It was the first pan India protest against the British colonial government, although this protest was majorly confined to the cities. To read more about the Rowlatt Act, check the linked article. 

Read more:

• Non Cooperation Movement
• Salt Satyagraha – History, Facts & Cause Of Salt March