The documents Snowden leaked detailed two NSA programs previously unknown to the general public. The first involved gathering and reviewing the telephone records of millions of Verizon wireless customers located in the U.S. A FISA court order issued in April 2013 required the company to provide information such as the location, time and duration of calls both within and outside the U.S., as well as the numbers of both parties on a continuing, daily basis. The order did not, however, cover the contents of any given call [source: Greenwald].
The Obama administration and others defended the program, citing various personal privacy safeguards as well as its importance to national security. They specifically noted that the "metadata" obtained didn't include actual underlying phone communications. As a result, FISA did not require an individualized warrant covering each person whose calls were swept up when the NSA reeled in its net [source: Roberts and Ackerman].
The "it's just metadata" argument went out the window when Snowden dropped another round of information, this time about government trolling of people's electronic communications. In a program called "PRISM," NSA collects individuals' Internet information, including search history, the content of e-mails and live chats and file transfers. According to a 41-slide PowerPoint presentation revealed by Snowden, the program is run with the assistance of computing giants like Google, Apple and Facebook, each of which has denied participation. [source: Greenwald and MacAskill].
FISA still bars the feds from spying on Americans' electronic communications and activities completely within the U.S. The problem is that it can be hard to tell whether a particular e-mail, chat or phone call is domestic or foreign. That means a lot of information that is supposed to be off-limits gets "inadvertently" included in the government hauls [sources: Drum, Friedersdorf].
Officials tout certain "minimization procedures" intended to limit the use of wrongly gained data and communications. While this information generally must be destroyed, a pretty big loophole allows the feds to keep and use the info if it relates to a "threat of harm to people or property" [sources: Drum, Friedersdorf].
We wouldn't know about these programs if not for Edward Snowden. Who is he, and how did he get his mitts on the goods?