Online content providers such as YouTube are carefully positioning themselves to users, clients, advertisers, and policymakers, making strategic claims as to what they do and do not do, and how their place in the information landscape should be understood. One term in particular, 'platform,' reveals the contours of this discursive work. 'Platform' has been deployed in both their populist appeals and their marketing pitches - sometimes as technical platforms, sometimes as platforms from which to speak, sometimes as platforms of opportunity. Whatever tensions exist in serving all of these constituencies are carefully elided. The term also fits their efforts to shape information policy, where they seek protection for facilitating user expression, yet also seek limited liability for what those users say. As these providers become the curators of public discourse, we must examine the roles they aim to play, and the terms with which they hope to be judged.