New doctoral book examines the regulatory complexities of online content moderation within the European Digital Single Market

On 26 September 2025, Silvia A. Carretta will defend her doctoral thesis in private law, entitled “Online Content Moderation. The regulatory continuum from EU regulation to platform self-regulation”. This PhD project is the first in cooperation between the Uppsala University’s Faculty of Law and the Wallenberg AI, Autonomous Systems and Software Program - Humanity and Society (WASP-HS).

In today’s digital landscape, users generate an extraordinary amount of content every minute. Some of this material poses serious legal challenges, including terrorist propaganda, copyright-infringing works, hate speech, and disinformation. Online platforms face increasing pressure to moderate such content effectively. They must comply with legal obligations to remove illegal material or risk liability, while remaining free to exercise discretion in enforcing private moderation policies to restrict lawful content they deem incompatible with their Terms and Conditions. This dual role raises pressing legal and societal questions regarding the balance between public regulation and the growing influence of private actors in governing online speech.

For the past three decades, scholars have examined the legal and political dimensions of online free speech, content moderation and platform regulation. They have asked what it means to moderate user-generated content, and if (and how) these intermediaries should be regulated. Recent shifts in content moderation practices on very large platforms reveal a shift from a zealous approach to content takedown, leaning towards overblocking of legal content (out of fear of liability) to a more permissive approach.

“This newer approach claims to prioritise user freedom of expression and reduce censorship by lifting restrictions on some topics that are part of mainstream discourse and focusing our enforcement on illegal and high-severity violations,” Silvia A. Carretta explains.

The adoption of the Digital Services Act (DSA) in 2022 marked a turning point in European research on platform governance. Researchers from multiple disciplines have assessed its impact on platform accountability and user rights, highlighting the DSA’s role in shaping the contemporary discourse on digital governance.

“However, while public regulation has been widely debated, there is a lack of insight into how the public and private regulatory spheres interact in this context”, Silvia adds.

For these reasons, Silvia focused her doctoral research on investigating how content moderation is regulated within the European Digital Single Market, as a key to designing fair, effective, and accountable platform governance policies. The research findings are presented in her doctoral book, published in August 2025. It is the first study to systematically map the regulatory continuum between binding EU law (most notably the DSA) and private governance mechanisms implemented by online platforms to enforce their Terms and Conditions (notably their Community Guidelines). According to Silvia, the two Regulation “of” platforms and Regulation “by” platforms dimensions should not be viewed as a dichotomy between public and private governance but as components of a dynamic, multi-actor regulatory process.

“This book explains how that ecosystem works — and where it needs reform”, Silvia continues.

This pioneering study systematically maps policy variables and governance instruments across a tripartite classification of the regulatory function – EU regulation stricto sensu, co-regulation and self-regulation. Through case studies of major online platforms, Silvia’s research examines how public and private regulatory frameworks interact, overlap, and sometimes conflict in shaping platform regulation and digital content governance.

A timely and rigorous analysis, the book critically reflects on the Digital Services Act’s transformative role in reshaping platform accountability and digital governance. Additionally, it offers a novel and comprehensive evaluation of whether, and to what extent, the selected online platforms comply with obligations arising from the new DSA framework and other sectoral obligations. It presents an important illustration of how alternative modes of regulation - i.e. co-regulation and self-regulation - are used by private online platforms, in their capacity as “private rule-makers”, to shape online public discourse, alongside binding public regulation.

Additionally, a dedicated chapter examines in detail how algorithmic content moderation works in practice, shedding light on the role of AI-based automated systems in regulating online speech.

“This study provides a timely and rigorous assessment of the evolving regulatory frameworks governing digital content”, Silvia concludes.

The book is intended for scholars, policy-makers and practitioners seeking to understand the latest regulatory framework behind platform governance and content moderation within the European Digital Single Market.