How did you come to choose your research topic?

I first had the idea to explore the issue of the exercise of the right to freedom of expression online while I was a master student here at the Institute. My interest was sparked by my own, personal experience as a social media user and the sense of disconnect I felt between what I was learning in class and what I instead witnessed online. If in the classroom I was learning all about how each individual has inalienable rights, how even non-state actors have, if not obligations in the sense traditional international law denotes them, at least responsibilities, my experience on social media made it quite evident how human rights seemed to be a rather neglected issue, despite their inherent importance for the exercise of the right to freedom of expression. One issue that I remember was quite decisive in making me pursue this line of inquiry was the rise of the antivax movement online around the years 2016–2017. I remember quite distinctly the proliferation of online posts and Facebook events for organising “smallpox parties”: the idea behind these events was that parents whose children had contracted smallpox would organise parties so that other children, who had not contracted the illness but were not vaccinated, could also get infected and become immune. These forms of expression were circulating seemingly without moderation, and I kept asking myself: is this legitimate expression? What about the right to health of these children? Alongside these incidents, other scandals were hitting social media companies. As I became more interested in these issues, the initial question of my then proposed thesis became quite evident: how can international human rights law effectively regulate private technology companies and social media platforms and, in particular, the right to freedom of expression as exercised on these platforms?

What was your methodology for approaching this question?

As I also illustrate in the thesis, the context in which the initial inspiration for my research topic arose changed rather suddenly. In a relatively quick amount of time, the language of human rights, whose absence had inspired my research question, became rather predominant in the discourse around platform regulation, and I kept witnessing these phenomena and following the uptake of human rights by a variety of actors. I therefore found myself having to change perspective: since human rights law had begun to regulate the exercise of freedom of expression online, it seemed fascinating to me to explore how we had gotten here. And this is why my thesis ultimately tells the story of how international human rights law became a dominant framework for regulating the exercise of freedom of expression online and of who made it happen. Importantly, it was my intention to also pay particular attention and seek to unveil what this could mean for international law more generally.

In telling this story, the first, fundamental step was the identification of its main characters. I identified UN human rights bodies, corporate entities such as Meta, and independent redress mechanisms such as the Oversight Board as the main drivers for the elevation of international human rights law as a dominant frame for addressing issues raised by commercial content moderation. I unpacked and analysed the expert input from the UN Treaty Bodies and Special Rapporteurs on issues related to the protection of the right to freedom of expression (both online and offline), as well as reports and materials from corporate entities (taking Meta as the main case study) and the “case-law” of the Oversight Board. Significantly, international law does not traditionally conceive these actors as primary subjects of the discipline.

What are your major findings?

I show how these actors, by engaging with and interpreting the normative content of the UN Guiding Principles on Business and Human Rights (UNGPs) in the context of online content moderation, have pushed for the development of norms and practices that go beyond the content initially envisaged by the UNGPs themselves, and have become the main drivers for translating the application of human rights law to the exercise of freedom of expression online.

In pointing the spotlight to these practices, my study makes two important contributions. 

First, drawing from Nico Krisch’s work, I demonstrate how the regulation of the right to freedom of expression as exercised online is, today, a site of “entangled legalities”. In particular, platform law is entangled both with domestic regimes and international human rights law. The level of interaction and entanglement of these regimes is determined by the actors who interpret and apply them. Importantly, the higher the level of entanglement between these regimes and international human rights law, the higher is the level of protection afforded to users. Human rights law, in this web of entanglement, can also serve to challenge domestic regimes when they are not themselves aligned with international human rights law. 

The second finding is that, by taking ownership of the language of international human rights law, UN human rights bodies, corporate entities, and private redress mechanisms have become drivers for change in international law. The emergence of international human rights law as a dominant framework for addressing content moderation issues originated in paths that are beyond traditional mechanisms for change in international law. These phenomena have therefore wider implications for international law as a discipline. In the thesis, I demonstrate how, starting from an ideational path and travelling through social practices, international human rights law ultimately emerged as one of those “legalities” that now regulates freedom of expression online. This demonstrates how legal change can occur outside those mechanisms that international law traditionally looks at, and actors other than states can be the drivers of legal change.

What are you doing now?

As of 1 April 2025, I have started a new position as Postdoctoral Researcher in Online Content Moderation at the Conservatoire National des Arts et Métiers in Paris. The position is part of the Cnam’s Chair in Humanities and Social Sciences, funded by the Île-de-France region and focused on online content moderation. Here, I will continue to work on the issue of online content moderation, focusing more specifically on EU law, and the EU Digital Services Act in particular. In the coming months, following the useful advice I received during my thesis defence, I will also start to prepare a book proposal based on my doctoral dissertation. In parallel, I am also maintaining my position as Visiting Lecturer at Riga Graduate School of Law, where I have been teaching a course on Business and Human Rights, and where I am currently supervising students writing their bachelor’s thesis.

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On 10 February 2025, Stefania Di Stefano defended summa cum laude avec félicitations du jury her PhD thesis in International Law, titled “Regulating Freedom of Expression in the Age of Social Media: New Actors as Drivers of Change in International Law”. Professor Andrea Bianchi (right) presided over the committee, which included Professor Andrew Clapham (left), Thesis Director, and Professor David Kaye, University of California, Irvine School of Law, USA.

Citation of the PhD thesis: 
Di Stefano, Stefania. “Regulating Freedom of Expression in the Age of Social Media: New Actors as Drivers of Change in International Law.” PhD thesis, Graduate Institute of International and Development Studies, Geneva, 2025.
A brief abstract of the PhD thesis is available on this page of the Geneva Graduate Institute’s repository. As the thesis itself is embargoed until March 2028, please contact Dr Di Stefano for access.

Banner image: image generated with the prompt “J'aimerais illustrer la régulation des contenus sociaux avec une loupe examinant un post” by Shutterstock, 9 May 2025.
Interview by Nathalie Tanner, Research Office.