Section 144 of the CrPC empowers a magistrate to issue a notified or ex-parte prohibitory order to individuals or groups of individuals in an area, usually in emergency situations, to prevent any bodily and mental harm, disruption of public peace and tranquility. According to my searches on the history of this particular section, it is mostly used against specific individuals on petitions filed by aggrieved parties who apprehend some danger to their persons or property. The order, for example, has in the past been issued by magistrates to prevent certain persons from encroaching on disputed property when approached by certain aggrieved parties; in such cases, the magistrates have also been known to pass similar orders against the original petitioners when demanded in turn by the prohibited parties. It is, in some form, a 'restraining order'. Orders under this section can be challenged in the high court of the state.
But in the past few months, the Indian government has gone nuts on this section. Section 144 of the CrPC has been invoked innumerable times to suppress public protests. The government uses this section now immediately when a major protest rally or demonstration attracts large numbers. The Congress Party is the most vicious abuser of this particular law. It used it recently in Delhi to disrupt the protests led by Baba Ramdev, and the state government in Assam used it as well to violently disrupt the KMSS-led anti-eviction rally. The law has become a handy tool to subvert the processes of democratic protest. The vague and arbitrary notion of 'public peace and tranquility' makes it possible for the authorities to clamp down on public interest movements when they become critical of state iniquities, corruption and acts of violence. When this section is imposed on a particular area, it is not possible to gather in large numbers to even protest peacefully, and the police are liable to round you up. This draconian colonial left-over law is clearly being put to its most opportunistic uses by current Congress governments at a time of growing public awareness and civic rights.