I gave a talk about this at the Oakland Cryptoparty back in October. The slides are a little patchy and based entirely on perusing the site (read: speculation), but it inspired a lively discussion from amongst all the participants. It seems there's nothing like illegal drugs and the black market to get people interested in learning more about crypto!
I'm planning on giving an updated version of this talk at "SF Cryptoparty II" on March 23rd (attend or sign up to talk! https://cryptopartysf.org/). I will definitely incorporate ideas from (and link back to) this article. Feedback appreciated!
Slides: http://garrett.im/static/pdf/silkroad_oakland_cryptoparty_sl...