The mid-1960s were the heyday of punch-card-powered mainframe computers. In the two decades since their invention, digital machines had proved capable of processing a dizzying amount of information. Much of this data was personal, from medical information to military records to the type of cereal families bought at the supermarket, and there were no legal limits on what kind of data could be collected or by whom. The targeted marketing business until then had been largely left alone by regulators because it was so inexact. The computer age, however, transformed consumer targeting into a far more powerful science.

Worries about data privacy erupted in the spring of 1964 with the publication of “The Naked Society,” by Vance Packard, a journalist best known for his unsparing critique of modern advertising. “The Naked Society” made a comparable assessment of the marketing schemes of big corporations, noting their immense and profitable traffic in personal data about American consumers. But he trained most of his attention on the entity that was then the largest user of mainframe computing power: the United States government.

Unnerving amounts of personal information now could be sucked into bureaucratic databases, Packard observed. “There are banks of giant memory machines that conceivably could recall in a few seconds every pertinent action — including failures, embarrassments or possibly incriminating acts — from the lifetime of each citizen,” he wrote.

Packard hit a nerve. Congress convened a Special Subcommittee on the Invasion of Privacy and started hearings into the government’s databank proposal in July 1966. The leading privacy crusader in the House, New Jersey’s Neil Gallagher, was a Johnson ally who believed that the databank had some merit but that the plan didn’t do enough to protect personal information. On the Senate side, North Carolina’s Sam Ervin was a critic of the president’s expansive domestic agenda and saw the databank as yet another sign of executive overreach. “The computer never forgets,” Ervin warned.