Legal debates over the "big data" revolution currently focus on the risks of inclusion: the privacy and civil liberties consequences of being swept up in big data's net. This short essay takes a different approach, focusing on the risks of exclusion: the threats big data poses to those whom it overlooks. Millions of people worldwide remain on big data's periphery. Their information is not regularly collected or analyzed, because they do not routinely engage in the sorts of behaviors big data is designed to capture. Consequently, their preferences and needs risk being routinely ignored when governments and private industry use big data and advanced analytics to shape public policy and the marketplace. Because big data poses a unique threat to equality, not just privacy, this essay argues that a new "data antisubordination" doctrine may be needed.