K.S. Puttaswamy v. Union of India (2017)

The 2017 judgment in K.S. Puttaswamy v. Union of India originated in a writ petition filed in 2012 by Justice K.S. Puttaswamy, a retired judge of the Karnataka High Court, challenging the Aadhaar biometric identification scheme as a violation of privacy. When the matter reached the Supreme Court, the Union of India argued that the Constitution contained no fundamental right to privacy, relying on two binding precedents decided by larger benches: M.P. Sharma v. Satish Chandra (1954), an eight-judge bench, and Kharak Singh v. State of Uttar Pradesh (1962), a six-judge bench. Because these earlier decisions could only be overruled by a still larger bench, a three-judge bench referred the privacy question to a Constitution Bench, which in turn constituted a nine-judge bench. On 24 August 2017, in Justice K.S. Puttaswamy (Retd.) v. Union of India (Writ Petition (Civil) No. 494 of 2012), the nine judges unanimously held that the right to privacy is a fundamental right protected as an intrinsic part of the right to life and personal liberty under Article 21 and as part of the freedoms guaranteed by Part III of the Constitution.

The procedural mechanics turned on the doctrine of stare decisis and bench strength. Since M.P. Sharma and Kharak Singh had cast doubt on the existence of a privacy right, only a bench of nine or more could authoritatively resolve the conflict, given that M.P. Sharma was an eight-judge decision. The nine-judge bench, led by Chief Justice J.S. Khehar, heard the reference solely on the threshold constitutional question of whether privacy is a guaranteed right, deferring the merits of the Aadhaar challenge to a separate bench. The Court delivered six concurring opinions spanning six judgments authored by Justices Chelameswar, Bobde, Nariman, Sapre, D.Y. Chandrachud (writing for himself, the Chief Justice, Justices Agrawal and Nazeer) and Kaul. All nine agreed on the outcome: M.P. Sharma was overruled to the extent it held privacy was not protected, and Kharak Singh was overruled insofar as it was internally inconsistent on the point.

The doctrinal core of the judgment is the articulation of a structured proportionality standard for assessing intrusions into privacy. Justice Chandrachud's plurality opinion held that any state limitation of the right must satisfy three conditions: legality, meaning the existence of a law; a legitimate state aim or need; and proportionality between the object and the means adopted to achieve it. Justice Kaul added a fourth element of procedural safeguards against abuse. The Court located privacy in three overlapping zones — the privacy of the body and intimate decisions, informational privacy concerning personal data, and the privacy of choice extending to political and personal autonomy. Significantly, the judgment also expressly overruled ADM Jabalpur v. Shivkant Shukla (1976), the notorious Emergency-era habeas corpus decision, holding that natural and inalienable rights do not depend on positive law for their existence.

The immediate downstream application came in Navtej Singh Johar v. Union of India (2018), in which the Supreme Court read down Section 377 of the Indian Penal Code to decriminalise consensual same-sex relations, and in Joseph Shine v. Union of India (2018) striking down adultery as a crime. The Aadhaar matter itself returned to a five-judge bench, which on 26 September 2018 upheld the constitutional validity of the Aadhaar Act, 2016 while striking down Section 57 and reading down mandatory linkage, applying the Puttaswamy proportionality test. The judgment also catalysed the legislative process culminating in the Digital Personal Data Protection Act, 2023, which the Union government enacted as India's first comprehensive data-protection statute after the withdrawal of earlier draft bills.

Puttaswamy must be distinguished from the right to information regime under the Right to Information Act, 2005, with which informational privacy frequently collides; the two rights are balanced rather than hierarchically ranked. It is also distinct from the common-law tort of breach of confidence and from the data-protection statutory framework, which operates at the sub-constitutional level. Whereas the Maneka Gandhi v. Union of India (1978) judgment expanded the procedural content of Article 21 to require fairness, Puttaswamy expanded its substantive content to embrace privacy and autonomy. The proportionality standard it imports is drawn from German and Canadian constitutional jurisprudence and differs from the older Wednesbury unreasonableness test that Indian administrative law had applied to executive action.

Controversy persists over the scope of permissible state surveillance. The 2021 disclosures concerning the Pegasus spyware prompted petitions invoking Puttaswamy, and in October 2021 the Supreme Court appointed a technical committee to investigate, observing that national-security claims cannot serve as a blanket bar to judicial scrutiny. Critics note that the judgment's promise of informational privacy was diluted by aspects of the 2018 Aadhaar verdict and by the DPDP Act's broad exemptions for state agencies. Debate continues over whether the proportionality test is consistently applied, particularly where surveillance, biometric data, and facial-recognition systems are concerned.

For the working practitioner, Puttaswamy is foundational reading for UPSC General Studies Paper II on the polity and fundamental rights, and indispensable for desk officers and policy researchers handling data governance, surveillance reform, and digital rights. It established the constitutional benchmark against which every data-protection rule, identity scheme, and surveillance authorisation in India is now measured, and it equipped Indian courts with a transplantable proportionality framework that has become the default analytical tool for adjudicating competing rights claims.