New slide published July 10

Upstream program

This slide shows PRISM as only one part of the NSA's system for electronic eavesdropping. The "Upstream" program collects from the fiber-optic cable networks that carry much of the world's Internet and phone data. The underlying map depicts the undersea cables that connect North America to the rest of the world.

Slides published June 29

Acquiring data from a new target

This slide describes what happens when an NSA analyst "tasks" the PRISM system for information about a new surveillance target. The request to add a new target is passed automatically to a supervisor who reviews the "selectors," or search terms. The supervisor must endorse the analyst's "reasonable belief," defined as 51 percent confidence, that the specified target is a foreign national who is overseas at the time of collection.

Analyzing information collected from private companies

After communications information is acquired, the data are processed and analyzed by specialized systems that handle voice, text, video and "digital network information" that includes the locations and unique device signatures of targets.

Each target is assigned a case notation

The PRISM case notation format reflects the availability, confirmed by The Post's reporting, of real-time surveillance as well as stored content.

Searching the PRISM database

On April 5, according to this slide, there were 117,675 active surveillance targets in PRISM's counterterrorism database. The slide does not show how many other Internet users, and among them how many Americans, have their communications collected "incidentally" during surveillance of those targets.

Original slides published June 6

Introducing the program

A slide briefing analysts at the National Security Agency about the program touts its effectiveness and features the logos of the companies involved.

Monitoring a target's communication

This diagram shows how the bulk of the world’s electronic communications moves through companies based in the United States.

Providers and data

The PRISM program collects a wide range of data from the nine companies, although the details vary by provider.

Participating providers

This slide shows when each company joined the program, with Microsoft being the first, on Sept. 11, 2007, and Apple the most recent, in October 2012.