The Trustycon folks have uploaded over seven hours' worth of talks from their event, an alternative to the RSA security conference founded by speakers who quit over RSA's collusion with the NSA. I've just watched Ed Felten's talk on "Redesigning NSA Programs to Protect Privacy" (starts at 6:32:33), an absolutely brilliant talk that blends a lucid discussion of statistics with practical computer science with crimefighting, all within a framework of respect for privacy, liberty and the US Bill of Rights.
Felten's talk lays out how the NSA's mass-collection program works, what its theoretical basis is for finding terrorists in all that data, and then explains how this is an incredibly inefficient and risky and expensive way of actually fighting crime. Then he goes on to propose an elegant alternative that gets better intelligence while massively reducing the degree of surveillance and the risk of disclosure.
I'm using Vid to MP3 to convert the whole seven hours' worth of talks to audio and plan on listening to them over the next couple of days.
Update: Here's that MP3 — it's about 1GB. Thanks to the Internet Archive for hosting it!