This report outlines the findings from the initial scoping phase of a project supported by a grant from Omidyar Network and launched by the Institute for Strategic Dialogue (ISD) and CASM Technology to identify online spaces used by extremist, hate and disinformation actors and communities as they increasingly move away from mainstream social media platforms. The report outlines the key barriers posed by these platforms to researching and mitigating harmful content and behaviours, and reviews existing research methodologies and tools to address these barriers. Finally, the report presents possible future scenarios for the evolving online ecosystem, and proposes a series of initial recommendations for policy-makers, platforms and the research community.