Design for security

I think you misunderstand me. I'm not talking about a system that has been "locked down" or "secured". I mean a computer system that is functionally indistinguishable from an inert lump of semi-precious metals. There might be a keyboard or mouse but it will never have an effect. There might be a screen but it will never display anything (information or otherwise). I think you understand this because you state why this is the case most effectively. If a system can be used(i.e. has any value of usability greater than absolute zero), then there is a potential (if unreasonable) system that is more secure because any security can be undermined by the user "working around it". Yes this is akin to a thought experiment. No-one is going to build an inert mass of metal and call it "the worlds most secure computer".

My point is that it is simple to imagine counter-examples to that initial idea that "Good experience design and good security cannot exist without each other" and i think that undermines the true value of what the talk is saying the rest of the time. I would rather people acknowledge that yes, there is a tension between usability and security and the interplay between these two values is complex and thinking about one without thinking about the other is doing your users a disservice.