In 1982, long before most Americans ever had to think about warrantless eavesdropping, the journalist James Bamford published The Puzzle Palace: A Report on N.S.A., America's Most Secret Agency," the first book to be written about the National Security Agency. In the book, Bamford describes the agency as "free of legal restrictions" while wielding "technological capabilities for eavesdropping beyond imagination." He concludes with an ominous warning: "Like an ever-widening sinkhole, N.S.A.'s surveillance technology will continue to expand, quietly pulling in more and more communications and gradually eliminating more and more privacy." Three decades later, this pronouncement feels uncomfortably prescient: we were warned. Incredibly enough, the Department of Justice, under Jimmy Carter, complied with Bamford's Freedom of Information Act requests, supplying him with secret documents related to the Church Committee, the Senate group that, in 1975, investigated American intelligence agencies for potential transgression of their mandates. That the government would hand over sensitive information to Bamford predictably infuriated the N.S.A.; Reagan Administration lawyers tried to bully Bamford into ceding his goods, threatening him with the Espionage Act, while the N.S.A. attempted to sequester the documents he'd uncovered. But because he was a lawyer, Bamford knew that he had done nothing wrong.