Massive Multiplayer Online Role-Playing Games (MMORPGs) are a sub-sector of virtual worlds that share with other worlds the characteristics of both complex technological systems and complex societies. The success of several MMORPGs makes them a vibrant area for research from different points of view, including their economic aspects (Castronova, 2005). Our research is mainly concerned with the practice of cheating in MMORPGs and its consequences. In this paper we explore the economic dimensions of cheating in MMORPGs as they relate to the business activities of companies that offer cheating software, in particular programs called 'bots'. Specifically, we address the following question: "How do cheating practices shape economic interactions around MMORPGs?" We characterize the economy of cheating (as it is carried out by cheating companies) as an answer to breakdowns in the relationship between cheaters and cheating companies (Winograd and Flores, 1987; Akrich, 1992), which involves both learning and innovation processes. In order to answer our question we present a case study of the Tibia (http://www.tibia.com) and an ongoing anti-cheating campaign. In the conclusion of the paper we provide some general reflections on the relevance of the economy of cheating to Virtual Worlds research.