anagama writes: Lots of new program names, flowcharts, and detail in four previously unreleased PRISM slides published by the WA Post today. These slides provide some additional detail about PRSIM and outline how the NSA gets information from those nine well known internet companies. Apparently, the collection is done by the FBI using its own equipment on the various companies' premises and then passed to the NSA where it is filtered and sorted.
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"