Abstract: India’s federal polity demands caution from those proposing surveillance law. Because the States are solely empowered to regulate law and order and the police, Union surveillance law must be careful not to exceed its bounds. However, in the Bharat Shah case, the Supreme Court disturbed this constitutional scheme. In any event, any law that seeks to regulate interceptions of communications must obey three principles: (i) the interception must be properly authorised, (ii) the interception must be based on ‘probable cause’, and (iii) the interception warrant must be strictly construed.