In this chapter, I demonstrate how Bourdieu's (1991) notion of symbolic instruments, that is structured and structuring structures, can be applied to the Internet to demonstrate the mediation and construction of knowledge and validation of expertise. This qualitative pilot study explored the online language and interrelationship between expertise, authority and constructions of knowledge. The structuring structures of five technology-focused websites are mapped in order to convey how the structured structures of online discourse mediate knowledge and expertise. The portrayal and authorization of "experts" within these online forums help to shape the way that knowledge is constructed, contested and shared in the twenty-first century. This article extends Bourdieu's (1990) theory of practice in two ways: (1) arguing that the Internet is a field comprised of many sub-fields, and (2) identifying some of the symbolic instruments that structure and are structuring knowledge and expertise via social media available on the Internet. [For the complete volume, "The Internet and the Google Age: Prospects and Perils," see ED576666.]