In 1968, the United States formed the House Subcommittee on Invasion of Privacy, which, according to the AP investigated, "data-gathering organizations and the dangers of unauthorized access to potentially damaging information." Much of the committee's formation was sparked by complaints of government agencies using certain psychological and personality tests during the hiring process. Opponents said gathering things like IQ tests and psychological fitness exams was an invasion of privacy.

Psychologists and experts still debate how much useful information can be gathered from these tests, but authors of The Assessment of Child and Adolescent Personality note that, at the time, "the basic issues involved the nature of undue invasion of privacy and the use of tests in situations for which they were not validated."

Ultimately this committee, along with another in the Senate, found no wrongdoing in the case of storing psychological tests. But it soon began hearing other complaints about security and privacy.

"Anything can be fed into the computers," Benjamin S. Rosenthal, a house representative from New York, said to the committee in 1968 with regards to computers storing information about people's credit history. "It can be fed erroneous information as well as it can be fed correct information. Within minutes, this false information can be disseminated to thousands of businesses, and can be very harmful to the individuals." Rosenthal went on to say computerized dossiers are being stored at the rate of 50,000 per week.

This "is just frightening to me," he said. Again, sound familiar?

Today we hear the same worries over surveillance tactics. Last year Senator Dianne Feinstein wrote that collecting US citizen's metadata like timestamp and duration of phone calls is necessary for law enforcement to "connect the dots" on criminals and doesn't violate the fourth amendment. Later, the ACLU of California provided a report showing that collecting "just metadata" painted a far more complete picture of people's lives than law enforcement lets on.

Defining "privacy" has always been a challenge. A practical and working definition in today's digital world has proven hard for even for experts. In 1967 the Office of Science and Technology took a shot with "the right of an individual to decide for him/herself how much he will share with others his thoughts, feelings and facts of personal life"—a right considered "essential to insure dignity and freedom of self determination." But that whether people are actually "deciding"—check your Facebook settings—and the "how much" part has always been the battleground. Any time we draw a line for what information we share about ourselves we open another set of implications.

That ends up being one of the key back and forth of the debate, both then and now: The party with the quantitative tools, whether they're tests or computers says, "We only want to know X." In response, watchdogs point out, "Yes, but that also allows you to know Y."