That's a ton of data to maintain. Last year, The Wire tried to figure out the physical footprint of the NSA's surveillance systems, given how much storage space is required for large amounts of data. Audio data takes up much more space than text data (and video data even more than audio). That's been a problem with RETRO, Gellman and Soltani report.

In the first year of its deployment, a program officer wrote that the project “has long since reached the point where it was collecting and sending home far more than the bandwidth could handle.”



Because of similar capacity limits across a range of collection programs, the NSA is leaping forward with cloud-based collection systems and a gargantuan new “mission data repository” in Utah. According to its overview briefing, the Utah facility is designed “to cope with the vast increases in digital data that have accompanied the rise of the global network.”

It's not clear what country served as the guinea pig for RETRO in 2011, or if it has since been extended to other nations. (The Post appears to have withheld the name of the first country.) MYSTIC is collecting phone communications in at least six countries, according to the annual intelligence budget, so it's possible that RETRO could be online in each.

It appears certain that Americans' data is collected, if they place or receive calls to or from target countries. The NSA is legally prohibited from surveilling Americans, but data and information about and from "U.S. persons" is regularly swept into the NSA's net through what it calls "incidental collection." The agency has to "minimize" the collection of Americans' data, but it's far from 100 percent. "[I]ntercepted communications 'may be retained and processed' and included in intelligence reports," Gellman and Soltani note. "The agency generally removes the names of U.S. callers, but there are several broadly worded exceptions."

Contacted for a comment, the NSA lashed out at the reporters. "[C]ontinuous and selective reporting of specific techniques and tools used for legitimate U.S. foreign intelligence activities," a spokesperson said in a statement, "is highly detrimental to the national security of the United States and of our allies, and places at risk those we are sworn to protect."

This article is from the archive of our partner The Wire.