Inside the Operating System Edward Snowden Used to Evade the NSA
It's worth noting that Tails doesn't make you impervious.  Tails uses Tor, and Tor is vulnerable to NSA and GCHQ attacks.  Specifically, they have the capability of deanonymizing individual targets.  I hypothesize that this capability works by monitoring Tor traffic worldwide, then performing a timing correlation between an origin and an endpoint.Here's an example:  Let's say (for the sake of example please) that the NSA can passively monitor Google searches in realtime.  Let's say you search for a phrase that sets off their monitor: something like "a Tor user has Googled for Snowden."  They'd like to know who you are.  How would they do that?One way is to record the fact that from your home computer originated some Tor traffic at almost the same time the Google search took place.It's unclear exactly how they deanonymize Tor users, but one piece of info that may corroborate my hypothesis is that in a Snowden screenshot, you can see the NSA has a tab called "Tor Events" in one of their tools.The need for websites to load quickly is Tor's Achilles heel, because it enables timing correlation.  The fact that few people use Tor exacerbates the problem.