Social media platforms have become an integral part of everyday lives and activities of most people, providing new forms of communication and interaction. These sites allow users to freely share information and opinions (in the form of photos, short texts and comments) as well as to promote the formation of links and social relationships (friendships, follower/followee relations). One of the most valuable features of social platforms is the potential for the dissemination of information widely and rapidly. The adoption of social media, however, also exposes users to risks, giving rise to what has been referred to as online harms.
Online harms are also widespread on social media and can have serious damaging effects on individuals and society at large. Different forms of online harms include, inter alia, the distribution of false and misleading content (such as hoaxes, conspiracy theories, fake news and even satiric content), harmful content such as abusive, discriminatory, offensive and violence-inciting comments, or the augmentation of societal biases and inequalities online. The proliferation of harms online has become a serious problem with several negative consequences, ranging from public health issues to the disruption of democratic systems (Online Harms White Paper, 2019). Identification of harmful content online has however proven difficult, with not only the scientific community but also social media platforms and governments worldwide calling for support to develop effective methods.