Social science is often concerned with the emergence of collective behavior out of the interactions of large numbers of individuals; but in this regard it has long suffered from a severe measurement problem—namely that interactions between people are hard to measure, especially at scale, over time, and at the same time as observing behavior. In this talk, I will argue that the technological revolution of the Internet is beginning to lift this constraint. To illustrate, I will describe three examples of research that would have been extremely difficult, or even impossible, to perform just a decade ago: (1) using email exchange to track social networks evolving in time; (2) using a web-based experiment to study the collective consequences of social influence on decision making; and (3) using a social networking site to study the difference between perceived and actual homogeneity of attitudes among friends. Although internet-based research still faces serious methodological and procedural obstacles, I propose that the ability to study truly “social” dynamics at individual-level resolution will have dramatic consequences for social science.