This Article provides the first comprehensive analysis of the law and policy of privacy on social network sites, using Facebook as its principal example. It explains how Facebook users socialize on the site, why they misunderstand the risks involved, and how their privacy suffers as a result. Facebook offers a socially compelling platform that also facilitates peer-to-peer privacy violations: users harming each others’ privacy interests. These two facts are inextricably linked; people use Facebook with the goal of sharing some information about themselves. Policymakers cannot make Facebook completely safe, but they can help people use it safely.
The Article makes this case by presenting a rich, factually grounded description of the social dynamics of privacy on Facebook. It then uses that description to evaluate a dozen possible policy interventions. Unhelpful interventions—such as mandatory data portability and bans on underage use—fail because they also fail to engage with key aspects of how and why people use social network sites. The potentially helpful interventions, on the other hand—such as a strengthened public-disclosure tort and a right to opt out completely—succeed because they do engage with these social dynamics.