The Supreme Court of India has played a foundational role in interpreting the ‘right to privacy’ in the context of surveillance and data protection, especially in the digital era. Its landmark pronouncements have established privacy as a fundamental right under the Constitution, and these judgments continue to guide legal responses to issues involving state surveillance, personal data misuse, and technological intrusions.

The most significant milestone came in the case of Justice K.S. Puttaswamy (Retd.) v. Union of India (2017), where a nine-judge Bench of the Supreme Court unanimously held that the right to privacy is a fundamental right under Article 21 (right to life and personal liberty) and other related freedoms under Part III of the Constitution. The Court emphasized that privacy includes not only bodily autonomy and personal space but also informational privacy, which is central to data protection. The judgment set the stage for legal scrutiny of surveillance practices and laid down that any intrusion into privacy must satisfy a three-fold test: (1) legality, (2) necessity, and (3) proportionality.

In the realm of state surveillance, the Court has acknowledged that surveillance can be justified in cases of national security or public order, but such surveillance must adhere to constitutional safeguards. In People’s Union for Civil Liberties (PUCL) v. Union of India (1997), which dealt with telephone tapping, the Court held that telephone conversations are protected under the right to privacy and that tapping can only be permitted by following legal procedures and under exceptional circumstances. The Court emphasized the need for oversight, accountability, and safeguards to prevent misuse of surveillance powers.

Although the Supreme Court has not yet delivered a comprehensive judgment on data protection legislation, it has reiterated the need for a strong legal framework to protect personal data. In the Puttaswamy case, the Court strongly urged the government to enact a law regulating how private and state actors collect, process, and store personal data. This led to the formation of the Srikrishna Committee on Data Protection, and eventually to the enactment of the Digital Personal Data Protection Act, 2023, although this law is yet to be tested for constitutional validity before the Court.

In conclusion, the Supreme Court has interpreted the right to privacy expansively, recognizing that in the age of digital technologies, data surveillance and unauthorized data usage pose serious threats to individual autonomy. The Court insists on constitutional safeguards and due process, and any form of surveillance or data collection must comply with the tests of legality, necessity, and proportionality. These principles are now central to any judicial review involving privacy rights in India.