Chapter 6 expands on the effects of collaboration and data in investigative reporting that were identified as growing international trends in Chapter 5. The chapter begins with a short history of data journalism, including its roots in computer-assisted reporting (CAR), and progresses to a comparative study of three of the most famous mega data leaks in recent journalism history: WikiLeaks, Edward Snowden’s National Security Agency (NSA) revelations, and the International Consortium of Investigative Journalism’s (ICIJ) Panama Papers. By doing so, different models of transnational investigative collaboration are explored. Original expert interviews with investigative reporters enable a deeper analysis of the societal implications of cross-media collaboration and use of big data in investigative reporting this century. The chapter argues that social science methods have become central to the role journalist’s play in analysing big data this century, which enables them to draw international attention to global power and its injustices in ways not previously possible. However, the negative impacts of the ‘big data’ age are also considered such as privacy breaches through mass data surveillance and other limits on press freedom. The chapter highlights mainstream media’s role in supporting (and criticising) these large-scale investigations, during a transformative period for news media.