There is a interesting talk on youtube [1] by William Binney (a former U.S. intelligence official turn whistle blower) [2], where he talks about the tech behind

There is a interesting talk on youtube [1] by William Binney (a former U.S. intelligence official turn whistle blower) [2], where he talks about the tech behind ThinThread [3]. He describes how ThinThread uses Latent semantic indexing [4] to pull together all this metadata into a type of fingerprint. There are various reports (see google) that Stellar Wind was based on a component of the ThinThread capability or that Stellar Wind was an off shoot of ThinThread. [1] https://www.youtube.com/watch?v=dxnp2Sz59p8 https://www.youtube.com/watch?v=dxnp2Sz59p8 [2] http://en.wikipedia.org/wiki/William_Binney_%28U.S._intelligence_official%29 http://en.wikipedia.org/wiki/William_Binney_%28U.S._intellig... [3] http://en.wikipedia.org/wiki/ThinThread http://en.wikipedia.org/wiki/ThinThread [4] http://en.wikipedia.org/wiki/Latent_semantic_indexing http://en.wikipedia.org/wiki/Latent_semantic_indexing