The chief instrument through which judicial activism has flourished in India is public interest litigation (PIL) or social action litigation (SAL). It refers to litigation undertaken to secure public interest and demonstrates the availability of justice to socially-disadvantaged parties and was introduced by Justice P. N. Bhagwati and Justice V.R. Krishna Iyer. It is a relaxation on the traditional rule of locus standi. Before 1980s the judiciary and the Supreme Court of India entertained litigation only from parties affected directly or indirectly by the defendant. It heard and decided cases only under its original and appellate jurisdictions. However, the Supreme Court began permitting cases on the grounds of public interest litigation, which means that even people who are not directly involved in the case may bring matters of public interest to the court. It is the court's privilege to entertain the application for the PIL.