Public release of datasets for Twin of an Online Social Network (TWON) project. To provide scientifically grounded evidence on the impact of online social networks (OSNs) on democratic debate, the project develops simulations of OSNs through digital replicas known as TWONs. Determining appropriate parameters for the underlying mathematical models—such as the weights used in large language models—requires robust empirical data. For this purpose, we have collected data from four key sources: online news monitoring (DS1), social media monitoring (DS2), individual data donations (DS3), and debate simulations (DS4). DS1: online news linked from DS2 DS2: social media (Twitter) data for USA user network data and German Replies Data DS3: individual data donations for German case study on communicating scientific uncertainty and Serbian case study on disinformation in Ukraine war DS4: simulated data for German political discourse on Twitter TWON (project number 101095095) is a research project, fully funded by the European Union, under the Horizon Europe framework (HORIZON-CL2-2022-DEMOCRACY-01, topic 07).