Recent advances in technologies broadly referred to as “artificial intelligence” (AI) have increased the awareness about serious ethical concerns related to the impact of AI on societies and individuals alike. These concerns also aroused the attention of regulators and lawmakers around the world, which are leading to proposals to ban certain AI systems or practices. As a concrete example, the present paper discusses the prohibited AI practices listed in Artificial Intelligence Act (AIA) proposed by the European Union (EU). Given their cross-cutting nature, these AI practices raise a number of complex and transdisciplinary questions that will be addressed by reference to their impact on human trust and cognition and the types of harm they may cause.