Caste system is systemic social and economic oppression of people based on graded hierarchical distinctions between different castes and sub-groups that they are born into. People who were not included within the four upper castes were often relegated to tasks considered unworthy (cleaning, garbage collection etc.) and excluded from sharing food and water from the same sources. Dalits (which means crushed or broken to pieces) have fought against caste oppression and exclusion since nineteenth century through spirituality and social movements for education and work. In 1952, under the Indian Constitution, those belonging to Scheduled Castes and Tribes were given specific rights and the law is meant to address and protect people from caste-based atrocities, violence, murder, rape, harassment and hate speech. Many atrocities against Dalits take place in instances of changing occupations, inter-caste marriages, targeted incidents of brutal violence, rape of women and similar incidents of everyday brutality. Dalits are often denied inclusion in various domains including academic, news, industry and cultural activities. Dalit politics particularly has been inspired by the writings and thought of Dr. Babasaheb Ambedkar (also the main person who drafted the Indian constitution). Among various social and cultural activities in different parts of India, annually people congregate at Chaityabhoomi which is a memorial for Dr. Ambedkar. In 1925, Periyar founded the Self Respect Movement (Dravidian movement) in Tamil Nadu, and in 1972, the Dalit Panthers was formed inspired by the revolutionary black organization Black Panthers. Dalits Media Watch, Dalit History Month, Roundtable India and others are the sources for most of the information collected on atrocities against Dalits.