The “open source” model initially emerged as a way for programmers to collaborate on efforts to build and share code, but has since evolved to embody an ethos of sharing and cooperation that pervades software development as a whole. As many technologists have seen, however, a philosophy of openness can leave them vulnerable to attempts by large corporations to use the norms of open source communities for their own benefits. This article examines the breach of social trust that occurs when companies do not fulfill expectations of reciprocity in their relationships with open source communities, and instead attempt to co-opt their work for monetary gain. Through analysis of three case studies, I seek to emphasize the often misleading nature of these processes and show that they are directly incorporated into the business models of large corporations, even if they are not openly acknowledged as such.