The revelations about secret National Security Agency programs, leaked by Edward Snowden earlier this month, have stirred great controversy, but this type of surveillance is not entirely new, according to journalist Shane Harris.
In his 2010 book, The Watchers: The Rise of America's Surveillance State, Harris traced the evolution of these surveillance programs in the U.S.
He says that as the digital age advanced, the NSA reached a crossroads and realized that analog tactics like phone tapping were quickly becoming obsolete: There was a whole new world of digital information to be accessed.
"They're realizing," says Harris, "if we can get into this 'digital network' ... [that] they would effectively be able to monitor global communications."
Because these communications were traveling through lines inside the United States, the U.S. was the central switching station for the global communications grid. The laws at the time, however, forbade much of that kind of intelligence gathering in the United States.
"9/11 changed all that," Harris tells Fresh Air's Terry Gross.
Harris is a reporter at Foreign Policy. He's also written about intelligence, surveillance and cybersecurity for the Washingtonian and National Journal.