BD and Metadata, etc.

Big data, metadata...

http://www.itworld.com/article/2829511/big-data/big-data--metadata--and-traffic-analysis--what-the-nsa-is-really-doing.html

http://www.itworld.com/article/2711540/it-management/faq--5-things-known-and-alleged-about-nsa-surveillance.html

http://www.itworld.com/article/2711310/security/report--nsa--fbi-collecting-content-from-google--facebook--other-services.html