Gherao , meaning "encirclement", is a word originally from Hindi . It denotes a tactic used by labour activists and union leaders in India, it is similar to picketing . Usually, a group of people would surround a politician or a government building until their demands are met, or answers given. This principle was introduced as a formal means of protest in the labour sector by Subodh Banarjee , the PWD and Labor Minister in the 1967 and 1969 United Front Governments of West Bengal , respectively. 
Owing to its popularity the word “gherao” was added to the Concise Oxford English Dictionary in 2004. Page 598 has the entry: “Gherao: n (pl. gheraos). Indian; a protest in which workers prevent employers leaving a place of work until demands are met; Origin: From Hindi” and Subodh Banarjee was referred to as the Gherao minister .  In usage, the past tense of the verb, gheraoed , is more common.