  We present MIDDAG, an intuitive, interactive system that visualizes the
information propagation paths on social media triggered by COVID-19-related
news articles accompanied by comprehensive insights, including user/community
susceptibility level, as well as events and popular opinions raised by the
crowd while propagating the information. Besides discovering information flow
patterns among users, we construct communities among users and develop the
propagation forecasting capability, enabling tracing and understanding of how
information is disseminated at a higher level.
