Critics from across the political spectrum attack social media platforms for invading personal privacy. Social media firms famously suck in huge amounts of information about individuals who use their services (and sometimes others as well), and then monetize this data, primarily by selling targeted advertising. Many privacy advocates object to the very collection and use of this personal data by platforms, even if not shared with third parties. In addition, there is the ongoing (and reasonable) concern that the very existence of Big Data creates a risk of leaks. Further, aside from the problem of Big Data, the very existence of social media enables private individuals to invade the privacy of others by widely disseminating personal information. That social media firms’ business practices compromise privacy cannot be seriously doubted. But it is also true that Big Data lies at the heart of social media firms’ business models, permitting them to provide users with free services in exchange for data which they can monetize via targeted advertising. So unless regulators want to take free services away, they must tread cautiously in regulating privacy.