The National Security Agency (NSA) has compiled an exhaustive guide on how to find
information on the internet. This fascinating 642-page guidebook called Untangling The Web (pdf) was written by Robyn Winder and Charlie Speight, and published by the NSA's
Center for Digital Content in 2007. Muckrock, a public records request service, was able to obtain the document through a Freedom of Information Act (FOIA) request.