A recent ruling by a federal court said that much of the phone data the NSA has been gathering from American citizens for years was collected illegally. That decision set off another round of debate over the scope of personal privacy in a democratic republic like ours, and the means by which the government “keeps tabs” on citizens. So in this episode, the Guys explore the changing ways we’ve collected information on each other – and when it crosses from something necessary into something invasive. From early attempts to determine people’s credit rating to the accumulation of data about Americans’ “racial purity,” the History Guys and their guests look at how, and why, Americans have kept tabs on each other, and consider how earlier generations have balanced the need-to-know with expectations of privacy.