This essay advances the thesis that the most influential and important political documents of the twenty-first century are not neces-sarily the constitutions and charters written for new or reconfigured nation states, but the often-overlooked terms of service agreements that users must sign (or, more precisely, click agree) in order to participate in social networks like Facebook, Second Life, Google+, Bebo, etc. These agreements, which constitute the principle governing documents of online social worlds (Grimes et al., 2008), constitute a kind of postmodern, post-nation state social contract. As such, they articulate, structure, and regulate not only the kind of social interactions and political opportunities that are available within these global networks but determine what forms of social activity and affiliation are considered to be appropriate, acceptable, and even possible. The examination, which takes a critical approach to this subject, will be divided into three parts. The first situates these agreements within the history and lineage of modern political thought in general and social contract theory in particular. The second pursues a critical reading of the Terms governing Facebook, a social network with a population of active users that now exceeds Brazil making it the fifth most populous polity on the plant. The final section extrapolates the broader social and political consequences of these agreements, arguing that informed users not only need to read these documents carefully but also need to recognize the way these seemingly unimportant texts define and delimit the very conditions of (im)possibility for social involvement and interaction in the 21st century. Although the subject addressed by the essay is contemporary and a product of the late 20th and early 21st centuries, the method of its presentation is rather anachronistic and deliberately dissimulates the rhetoric and tone of an 18th century treatise. And this has been done, I can tell you dear reader, not out of affectation, but because the subject matter will have required nothing less.