Maritime piracy is analysed using social constructionist theories. Societal reactions toward behaviour historically labelled piracy have been influenced by coastal state social constructions of ocean-space. Contemporary state-societal reactions resulted in internationalised piracy law and reporting processes by the International Maritime Organization (IMO), the International Maritime Bureau (IMB), and media, which show which types of particular maritime theft fall under the rubric of ‘piracy’. The reporting of this social problem by institutions shows them acting as moral entrepreneurs. Certain nations’ securitised reactions to piracy and private military companies’ commodification of anti-piracy solutions are explored. The International Transport Workers’ Federation’s reaction to piracy forms part of its moral crusade against flags of convenience (FOCs). It criticises these flags, which reportedly lack political will and insufficient infrastructure to counter piracy. Terrorist groups have also reportedly utilised FOCs. While piracy is mostly a problem for capital, however, FOCs remain purportedly, a problem for labour. Some radical unionists have used the term piracy to describe exploitative labour practices, (the theft of maritime labour) on FOC vessels. Charismatic environmental organisations have also used the term ‘piracy’, expanding the definition to refer to illegal fishing and whaling and highlighting a range of their activities using anti-piracy rhetoric. The dissertation examines why the environmental expansion of the definition of piracy has won greater acceptance than the Labourite construction of piracy in relation to FOCs. It concludes that there is a new postmodern stage of the global piracy prohibition regime.