A special issue of Big Data presents a series of insightful articles that focus on Big Data and Social and Technical Trade-Offs. Despite the dramatic growth in big data affecting many areas of research, industry, and society, there are risks associated with the design and use of data-driven systems. Among these are issues of discrimination, diversity, and bias, which are discussed in the papers in the special issue organized by Guest Editors Solon Barocas, Princeton University, danah boyd, Microsoft Research and Data & Society Research Institute, Sorelle Friedler, Haverford College, and Hanna Wallach, Microsoft Research and University of Massachusetts Amherst.