This article tries to better understand what Burke calls instrumental causes or technologies as tools that mediate human desire. Functioning as conduits that link humans to their lifeworld, instrumental causes are underwritten by agenic capacities imbued over long histories of cultural-historical use; further, as mediating technologies, digital tools provide creative solutions to the contradictions that develop from destabilizations in any activity system. While investigating the historical and cultural role mediating technologies play in digital spheres, I foreground Rhetorical Genre Studies to emphasize the rhetorical role objects play in structuring human activity. Looking beyond early articulations of genre as either form or substance, a RGS approach to digital tool mediation highlights the essential elements of interface and medium in understanding the social, political, and cultural traces circumscribed in objects like tagging systems and augmented browsing scripts. Analyzing digital tools as rhetorical genres that assist users in achieving conscious, goal-directed action helps Writing Studies analysts better understand the novel ways that tool mediation is inscribed with cultural-historical histories of use. This approach problematizes instrumentalist approaches to digital tool mediation by positioning digital objects as instrumental causes, not merely instruments. To demonstrate this method, I analyze the participatory archive of a piracy community, drawing special attention to the digital tools that mediate user activity.