A distinct but parallel set of questions now exists about certain digital platforms. A small number of companies-some governed by dual-class share structures-have immense power over social behavior, human health, and the information ecosystem. Yet, despite the enormous externalities generated by their business models, digital platforms remain virtually unregulated. This Article addresses two primary questions. First, have some digital platforms attained systemically important status? And second, if so, does their systemic importance warrant enhanced regulatory oversight? In addressing those questions, we consider parallels with financial regulation, drawing lessons from the framework for systemically important financial institutions in the Dodd-Frank era.