"Harmful actors use an ever-expanding range of digital spaces to spread harmful ideologies and undermine human rights and democracy online. Understanding their evolving ideas, online networks and activities is critical to the development of a more comprehensive evidence base to inform effective and proportional efforts to counter them. But generating that evidence base can challenge the technical capabilities, resources and even ethical and legal boundaries of research. We are concerned that these issues may be worsening just as the options for spreading harm online increase. This difficulty in conducting digital research systematically, ethically and legally results in a situation where trade-offs have to be made between competing priorities, including the desire to understand and mitigate harmful content and behaviours online, the preservation of privacy and the adherence to legal agreements. We argue in this report that this does not need to be the case; solutions are available, and actions should be taken as soon as possible to ensure a future-proof scenario in which researchers have the tools to monitor, track and analyse harmful content and behaviours systematically, ethically and legally. This report outlines the findings from the research phase of a project by the Institute for Strategic Dialogue (ISD) and CASM Technology; it is funded by Omidyar Network. The aim of the project is to identify and test research methodologies for monitoring and analysing small, closed or hardly moderated platforms. The report provides applied examples and evidence for the limitations and dilemmas encountered by researchers. In three short research case studies, focusing on Telegram, Discord and Odysee (in German, English and French respectively), we seek to apply different methodological approaches to analyse platforms that primarily present technological, ethical and legal, or fragmentation barriers." (Executive summary)