NSA data-mining 101: two 'top secret' programs and what they do

In the name of fighting terrorism, the US government has been mining data collected from phone companies such as Verizon for the past seven years and from Google, Facebook, and other social media firms for at least four years, according to government documents leaked this week to news organizations.

The two surveillance programs – one that collects detailed records of telephone calls, the other that collects data on Internet-based activities such as e-mail, instant messaging, and video conferencing – were publicly revealed in "top secret" documents leaked to the British newspaper the Guardian and the Washington Post. Both are run by the National Security Agency (NSA), the papers reported. 

The existence of the telephone data-mining program was previously known, and civil libertarians have for years complained that it represents a dangerous and overbroad incursion into the privacy of all Americans. What became clear this week were certain details about its operation – such as that the government sweeps up data daily and that a special court has been renewing the program every 90 days since about 2007. But the reports about the Internet-based data-mining program, called PRISM, represent a new revelation, at least to the general public. 

Data-mining can involve the use of automated algorithms to sift through a database for clues as to the existence of a terrorist plot. One member of Congress claimed this week that the telephone data-mining program helped to thwart a significant terrorism incident in the United States "within the last few years," but could not offer more specifics because the whole program is classified. Others in Congress, as well as President Obama and the director of national intelligence, sought to allay concerns of critics that the surveillance programs represent Big Government run amok.

But it would be wrong to suggest that every member of Congress is on board with the sweep of such data mining programs or with the amount of oversight such national-security endeavors get from other branches of government. Some have hinted for years that they find such programs disturbing and an infringement of people's privacy. Here's an overview of these two data-mining programs, and how much oversight they are known to have. 

1 | 2 | 3 | 4

Next