This report presents findings from the REASSURE (Researcher, Security, Safety, and Resilience) project’s in-depth interviews with 39 online extremism and terrorism researchers. Based at universities, research institutes, and think tanks in Europe and North America, the interviewees studied mainly, albeit not exclusively, far-right and violent jihadist online activity. The report catalogues for the first time the range of harms they have experienced, the lack of formalised systems of care or training, and their reliance therefore on informal support networks to mitigate those harms.