This synthesis presents the works of several key scholars in the field of critical data studies to explore how the practice of Big Data surveillance is redrafting possibilities for digital citizenship and contemporary democracy. Through a critical analysis of five works, I establish that the distinction between public and private surveillance is becoming ever-more unclear. In this light, I explore how the technology interfaces with inequality, transparency, and online participation, calling into question the validity, ethics and consequences of Big Data surveillance. I discuss how these phenomena construct ambivalent digital citizens who are both willing participants and fearful subjects in their online activities. I conclude that transparency, democratic accountability and novel forms of activism and policymaking are needed to counter the use of Big Data as a tool of political control and manipulation.