The vision of a borderless world, of people, ideas and products freely circulating within a self-regulating market, is one that clashes with the emerging legal regime based on the punitive force of the state. After a period of liberalization, seen in the opening of national economies and the promotion of regional trade projects and free-trade zones, the ambivalence of neoliberalism is manifest in a borderless capitalism that ambiguously depends on the securitization of national borders. Such a changing regime of state intervention is clearly seen at the Iguazú triangle – the tri-border urban conglomerate that straddles Brazil, Paraguay and Argentina – where the illegality of informal cross-border trading has been tolerated for decades. Recently stepped up police raids and controls hinder the passage of people and goods, while a new fiscal regime introduced in 2009 in Brazil attempts to regularize cross-border trafficking by turning petty smugglers into micro entrepreneurs. Petty smugglers – dubbed sacoleiros– can hardly be defined as entrepreneurs and do not constitute an identifiable category of entrepreneurship but, as typical in the informal sector, act on opportunity and need. Drawing on ethnographic research, this paper contextualizes the programmes for border controls and regularizing smuggling inspired by neoliberal ideology in South America.