The Supreme Court directed that peaceful, unarmed protesters in Delhi cannot be detained except in strict accordance with 'procedure established by law' under Article 21. The ruling arose from a crackdown on demonstrators linked to the Citizens for Justice and Peace (CJP). The Court reaffirmed that both the right to protest under Article 19(1)(b) and personal liberty under Article 21 impose a procedural obligation on the State before any detention is effected.

Article 21 guarantees that no person shall be deprived of life or personal liberty 'except according to procedure established by law.' The phrase, borrowed from the Japanese Constitution, was initially interpreted narrowly in A.K. Gopalan v. State of Madras (1950), where the Supreme Court held that 'procedure established by law' meant any procedure enacted by a competent legislature — without scrutiny of its fairness or justness.

The watershed came in Maneka Gandhi v. Union of India (1978), where a seven-judge bench overruled Gopalan's silos approach. The Court held that Articles 14, 19, and 21 are not mutually exclusive; any law depriving personal liberty must satisfy the 'golden triangle' — it must be fair, just, and reasonable (Art. 14), it must not unreasonably restrict fundamental freedoms (Art. 19), and the procedure must be reasonable, not arbitrary (Art. 21). Maneka Gandhi effectively imported the American 'due process' standard into Art. 21 without textually adopting it.

Preventive detention sits at the sharpest edge of this doctrine. Articles 22(1) and 22(2) guarantee the right to be informed of grounds of arrest and to consult a lawyer. But Article 22(3) exempts preventive detainees from these guarantees — making the 'procedure established by law' requirement in Art. 21 the primary safeguard. The SC's Delhi protest order reinforces that even where police invoke preventive detention statutes, the procedure used must be lawful, non-arbitrary, and judicially reviewable.

The right to peaceful assembly under Article 19(1)(b) is subject only to reasonable restrictions under Art. 19(3) — on grounds of sovereignty, public order, or morality. Detention of peaceful, unarmed protesters without following prescribed procedure simultaneously violates Art. 19(1)(b) and Art. 21, triggering the 'golden triangle' test established in Maneka Gandhi.