The digital world is prone to manipulation. Data do not just represent phenomena, but they also provide the means to act upon our world. Nowadays, the central role of digital data and their concentration in the hands of a few actors opens up new avenues for all sorts of manipulations. Some extreme cases have been highly publicized and widely discussed, in particular in the context of national elections. However, the precise role of the stakeholders involved and the impact of the manipulations are still not fully established. More fundamentally, the very definition of manipulation is not obvious and needs to be better understood in relation to digital societies. Last but not least, effective means to prevent manipulation are not easy to devise and can themselves have adverse effects. The goal of this panel is to discuss in a multidisciplinary way the issues raised by online manipulation, including the following questions:
• How can online manipulation be characterised and be distinguished from influence or nudging?
• How to draw a line between what can be accepted and what should be banned?
• When manipulation is based on the exploitation of human biases, how can it be identified and fought?
• What kind of legal and technical instruments could be used to effectively prevent or reduce the adverse effects of manipulation? What should be the role of the media in this context?