MYSTIC: The NSA's Telephone Call Collection Program

The Washington Post is reporting on an NSA program called MYSTIC, which collects all -- that's 100% -- of a country's telephone calls. Those calls are stored in a database codenamed NUCLEON, and can be retrieved at a later date using a tool codenamed RETRO. This is voice, not metadata.
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.