Ten Risks of PKI: What You're Not Being Told About Public Key Infrastructure is a paper by Carl Ellison and Bruce Schneier. These aren't technical risks, at least not directly, and it makes for interesting reading. (And after you're done reading your printed copy of the PDF you can leave it out in a strategic spot for other people to run across.)

(From this comp.lang.python article by Edward Elliot, which I ran across through the Daily Python URL.)