Hi!
This is the slides from my PSES2014's talk on nsa-observer.net, You can watch it here : pses2014.libwalk.so.
Feel free to (re)use it. It's under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) with the framework reveal.js.
You can watch the talk on ubicast.eu or on youtube (but it's in french ^^').
With datalove,
Skhaen (@skhaen)