Chapter 5 focuses on the regulation of social media platforms and platform architecture, with changes in EU perceptions regarding the reliability of these platforms and the values of their owners. It examines the shift from economically motivated self-regulatory regimes in these sectors based in logics of efficiency to a digital sovereignty-motivated move to a logic of security in regulation. It identifies the explicit linkage between economic and security concerns, particularly as it relates to disinformation and political advertising, with the promotion of co-regulatory regimes with significant levels of oversight provided by the Commission. It explores the approach to regulatory export adopted in these initiatives, with an emphasis on control of platforms regardless of where they are based, so long as they offer services in the EU.