In the age of hacking and whistleblowing, the internet contains massive troves of leaked information containing goldmines of newsworthy revelations in the public interest - if you know how to unravel them. For investigative journalists or amateur researchers with or without prior programming knowledge, this book gives you the technical expertise to find and interrogate complex datasets, transforming unintelligible files into ground-breaking reports. Through hands-on assignments and examples that highlight real-world cases, information security expert and well-known investigative journalist Micah Lee guides you through the process of analysing leaked datasets from governments, companies, and political groups. You'll dig into hacked files from the BlueLeaks dataset of law enforcement records, analyse social media traffic from those behind the 2021 insurrection at the US Capitol, hear the exclusive story of privately leaked data from the anti-vaccine group America's Frontline Doctors, and much more. You'll also learn the technical skills and Python programming basics needed for data science investigations, security concepts like disk encryption, how to work with data in JSON, CSV, and SQL formats, and tricks for using the command-line interface to explore datasets packed with secrets just waiting to be discovered.