--- - |2 Abstract Criminology is an applied discipline where the findings from the data collected and analyses conducted inform debates about policy and practice. For this to happen, a discipline must have an agreed‐upon set of facts to define the problem and suggest solutions. We can debate the soundness of fundamental data series, but these debates must take place within the confines of scientific inquiry and all data must be subjected to the same scrutiny. Data sources must comprise agreed‐upon standards for collection and be accessible for replication. The increasing use of “big data” has frayed this agreement about quality and accessibility and has made it more difficult for criminology to have its own facts. In this presentation, I define the term “big data” and argue it will be difficult for big data to replace traditional data sources and to live up to their potential for knowledge building. Finally, I suggest a few things that the discipline might do to address these problems of access and quality. - Criminology, Volume 56, Issue 3, Page 437-454, August 2018.