India, Oct. 11 -- The Supreme Court's direction that peaceful, unarmed protesters in Delhi cannot be detained except in accordance with the "procedure established by law" invokes one of the Constitution's most consequential protections against arbitrary State action.

Issued amid allegations of mass detentions, restrictions on movement and the suspension of internet services during Saturday's protest against chief election commissioner Gyanesh Kumar, the direction places a constitutional question at the heart of the controversy: can the State curtail personal liberty merely by invoking public order, or must every such restriction withstand legal and constitutional scrutiny?

A special bench of justices Joymalya Bagchi and V Mohana, hearin...