The untargeted program, called Dishfire, extracts information including location, contact networks and credit card details from SMS messages, the documents revealed.
While U.S. citizens' communications are mostly removed or "minimized," the documents suggested, text messages from other countries are retained in the system.
The Guardian obtained a Wikipedia-style guide to the program provided to GCHQ, the NSA's British counterpart, from former NSA contractor Edward Snowden. One ominous presentation from 2011 on Dishfire was entitled "SMS Text Messages: A Goldmine To Exploit." The agency also said a program called Prefer that extracts further information from automated text messages--texts sent with international roaming charges, missed call alerts--offered up rich "analytic gems" for exploitation.
The average daily tally of some of those "gems," from the Guardian:
More than 5 million missed-call alerts, for use in contact-chaining analysis (working out someone’s social network from who they contact and when)
• Details of 1.6 million border crossings a day, from network roaming alerts
• More than 110,000 names, from electronic business cards, which also included the ability to extract and save images.
• Over 800,000 financial transactions, either through text-to-text payments or linking credit cards to phone users
Clearly the text message collection is more distressing to non-U.S. citizens like the British whose communications can be kept in the system, as one of the GCHQ documents described Dishfire as collecting "pretty much everything it can."
An NSA spokeswoman told the Guardian that any implication the NSA's collection is "arbitrary and unconstrained is false," asserting that its activities are only directed against "valid foreign intelligence targets" and subject to strict legal safeguards.
Image via Shutterstock / TATSIANAMA