The National Security Agency has declassified a version of an in-house training manual used to teach NSA members how to best utilize the internet for research purposes. Untangling the Web: An Introduction to Internet Research was written by Robyn Winder and Charlie Speight and published by the NSA's Center for Digital Content back in 2007. It's been declassified and made available now following a Freedom of Information Act requested lodged by MuckRock back in April.

The document weighs in at over 600 pages, and tends to be geared towards an audience that may not necessarily be familiar with or see the value of the internet in research (then again, it's important to remember that the book was published six years ago). While chapters like "Search Fundamentals" and "Why Do I Need Help?" paint a basic picture, it also dives a bit deeper with sections like "Google Hacking," which focuses on "using publicly available search engines to access publicly available information that almost certainly was not intended for public distribution." Confidential company data, secret government information, and financial data are all listed as the types of data such searches could uncover.

Of course, there's been a huge uptick in online security awareness since Untangling was first written, to say nothing of the way search engines themselves have evolved. Nevertheless, the fundamentals still apply, and it's a fascinating look at what the NSA was thinking back in 2007.