Serious concerns have been raised about social media's and online news outlets' contributions to a pandemic of misinformation. The sheer volume, its spread, and the tendency of misinformation to exploit people’s cognitive biases have eroded the public's trust in media outlets, governmental institutions, and the democratic process.

This workshop aims to bring together designers, developers, and thinkers across disciplines to redefine computing systems by focusing on technologies, such as recommender and social computing systems. The workshop aims at fostering the development of applications that detect and limit the spread of misinformation as well as interfaces that instil and nurture critical thinking in their users. By focusing on the problem of misinformation and users’ cognitive security from a computing and HCI perspective, this workshop will sketch out blueprints for systems and interfaces that contribute to advancing media literacy, building critical thinking skills, and helping users tell fact from fake.