Prof. Dr. Matthias C. Kettemann, LL.M. (Harvard)

Senior Researcher "Regulatory Structures and the Emergence of Rules in Online Spaces"

Prof. Dr. Matthias C. Kettemann, LL.M. (Harvard) is head of the research program “Regulatory Structures and the Emergence of Rules in Online Spaces” at the Leibniz Institute for Media Research | Hans-Bredow-Institut (HBI). His team investigates the rules under which new forms and practices of social understanding and self-assurance emerge in digital communication spaces, and especially in social networks.

After studying law in Graz, Geneva and as a Fulbright and Boas scholar at Harvard School, he completed his doctorate with a thesis on the legal status of the individual in international law. In 2014, he was called to the Cluster of Excellence “The Formation of Normative Orders” at Goethe University Frankfurt as a postdoctoral researcher, where he habilitated with Prof. Kadelbach and Prof. Vesting at the Institute for Public Law at Goethe University Frankfurt am Main. His thesis was on the normative order of the internet and he was awarded the authorisation to teach international law, internet law and legal theory. After substitutions in Heidelberg and Jena, he followed the call to the professorship for innovation, theory and philosophy of law at the Institute for Theory and Future of Law at the University of Innsbruck in autumn 2021.

Other Activities

In addition to his work at the HBI, Matthias C. Kettemann is the head of the research group “Global Constitutionalism and the Internet” and the research project “The Public International Law of the Internet” at the Alexander von Humboldt Institute for Internet and Society (HIIG) in Berlin. He is also the director of the Innsbruck Quantum Ethics Lab, the rapporteur for quantum computing at the UNESCO World Commission on Ethics in Science and Technology (COMEST), a member of the board and the research group leader for “Platform and Content Governance” at the Sustainable Computing Lab at the Vienna University of Economics and Business, as well as the AI theme sponsor for the funding guideline on innovation impact assessment at the Federal Ministry of Education and Research (BMFTR).

Contact information

Prof. Dr. Matthias C. Kettemann, LL.M. (Harvard)

Senior Researcher "Regulatory Structures and the Emergence of Rules in Online Spaces"

Leibniz Institute for Media Research, Hans-Bredow-Institut
Warburgstraße 30b
20354 Hamburg

Last update: 12.11.2025

Works by Prof. Dr. Matthias C. Kettemann, LL.M. (Harvard)

Publikation Open Access Publication

Determinants of Verification Behavior in Generative Search

Generative AI is being increasingly integrated into search engines, but it has been criticized for producing content that sounds plausible yet is sometimes inaccurate. Little is currently known about the factors that prompt users to verify these responses. The study by Eva-Luise Knor, Michael V. Reiss, Judith Möller, and Lisa Merten addresses this knowledge gap.

Publikation Recently Published

Platforms, Online Surveillance, and the European Union: The Digital Services Act (DSA)

In their open-access article, Prof. Dr. Judith Möller, Ronan Ó Fathaigh, Bengi Zeybek, and Rocco Bellanova explore how the DSA facilitates public and private surveillance practices regarding content disseminated on online platforms.

Cover of issue 2/2026 M&K
Publikation Open Access Publication

M&K 2/2026 Has Been Published

The February 2026 issue of M&K features articles that explore the understanding of roles and the transformative potential of peripheral actors in the DACH region. Other articles examine developments in sports coverage in German daily newspapers from 2011 to 2021 and the usage patterns of ChatGPT, as well as anthropomorphic role attributions. You can download all of these articles free of charge.

Front Page of the Working Paper
Publikation Working Paper Available for Download

Babies and Toddlers in Family Influencing

In what ways and how often are babies and young children (ages 0–5) depicted on commercially oriented German-language social media profiles on Instagram, TikTok, and YouTube? Stephan Dreyer, Claudia Lampert, Kira Thiel, and others analyze this question using qualitative and quantitative methods. They also critically discuss the findings in light of the applicable legal framework and media ethics considerations.

Publikation Open Access Publication

Assessing Age Assurance Technologies: Effectiveness, Side-Effects, and Acceptance

In the article “Assessing Age Assurance Technologies: Effectiveness, Side-Effects, and Acceptance,” Dr. Wouter Lueks, Dr. Stephan Dreyer, Prof. Dr. Hannes Federrath, and Prof. Dr. Judith Simon analyze existing age verification methods.

Publikation Review of a Dissertation

Government Public Relations in New Media

For years, the democratic legitimacy of government public relations has been a topic of discussion in academic literature and constitutional jurisprudence. Tobias Mast reviews a recently published dissertation on the subject, exploring the untapped potential of interdisciplinary legal scholarship in relation to commonly accepted empirical assumptions.

Publikation Article for Friedrich-Ebert-Stiftung

Platform Badges for Civic Communication

Digital platforms have become central infrastructures for political communication and social negotiation processes. In his article, Jan Rau examines platform badges, which are tools that platforms use to fulfill their obligation to mitigate risk by creating positive incentives for users to adhere to certain communicative norms.

Cover des Arbeitspapiers
Publikation Working Paper for Download

Responsibility in the Platform Quadrangle

This working paper by Tobias Mast comments on the European Court of Justice's recent Russmedia ruling and sets out the premises for a relationship between EU legal acts in the digital single market that respects fundamental rights.

ein Kabel führt in ein Smartphone
Projekt Project with Helmut Schmidt University

Data Collection and Analysis on TikTok and YouTube

In order to develop the best practices for collecting and analyzing data on short video platforms, Gregor Wiedemann's Media Research Methods Lab at the HBI is participating in a Helmut Schmidt University project examining the German Armed Forces' representation on TikTok and YouTube.

Eine Fernbedienung zeigt auf einen Bildschirm mit unscharfen bunten Bildern
Projekt International Cooperation Project

Euromedia Ownership Monitor

The Euromedia Ownership Monitor provides policymakers and the general public with in-depth insights into the extent of media ownership transparency in the EU. It was updated in 2025.

Cover of the special issue on datafication, 1/2026, M&K
Publikation M&K Issue 1/2026 Published Open Access

On the Datafication of Communication

The special issue of M&K titled "The Datafication of Communication: New Methodological Approaches and Challenges" has been published as Issue 1/2026. The guest editors are Julia Niemann-Lenz, Tim Schatto-Eckrodt, Emese Domahidi, and Merja Mahrt.

Cover of the book
Publikation Article Published in Handbook

Growing Up in Data-Intensive and Automated (Media) Environments

Dr. Claudia Lampert examines changing usage practices and possible implications for socialization research in the chapter “Growing Up in Data-Intensive and Automated (Media) Environments” of the handbook “Media Socialization in ‘Smart’ Environments. Self- and Social Development in the Context of Datafication and Automation,” edited by Laura Sūna and Wolfgang Reißmann.

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