Robert Lemos from TechBeacon has written an excellent article on the tradeoff between security and usability: Security and usability go hand in hand: 5 tips to get the development mix right.
I'm obviously biased because he spent a lot of time discussing the issues with me (and used many of my comments in the article), but he also interviewed excellent developers who extended my comments and discussed the implementation issues in more detail.
Thank you, Robert.
Also see my articles:
And two book reviews: