The National Security Agency has built a surveillance system capable of recording “100 percent” of a foreign country’s telephone calls, enabling the agency to rewind and review conversations as long as a month after they take place, according to people with direct knowledge of the effort and documents supplied by former contractor Edward Snowden.

Some of the documents provided by Snowden suggest that high-volume eavesdropping may soon be extended to other countries, if it has not been already. The RETRO tool was built three years ago as a “unique one-off capability,” but last year’s secret intelligence budget named five more countries for which the MYSTIC program provides “comprehensive metadata access and content,” with a sixth expected to be in place by last October.

http://www.washingtonpost.com/world/national-security/nsa-surveillance-program-reaches-into-the-past-to-retrieve-replay-phone-calls/2014/03/18/226d2646-ade9-11e3-a49e-76adc9210f19_story.html


и Шнейер уточняет

What's interesting here is not the particular country whose data is being collected; that information was withheld from the article. It's not even that the voice data is stored for a month, and then deleted. All of that can change, either at the whim of the NSA or as storage capabilities get larger. What's interesting is that the capability exists to collect 100% of a country's telephone calls, and the analysis tools are in place to search them.

https://www.schneier.com/blog/archives/2014/03/mystic_the_nsas.html