Nobody does thoroughly argued presentations quite like Sebastian. This is good stuff on ethics and design.
I decided to share some thoughts it sparked via Twitter and ended up ranting a bit:
I recently talked about ethics to a bunch of “behavior designers” and found myself concluding that any designed system that does not allow for user appropriation is fundamentally unethical because as you rightly point out what is the good life is a personal matter. Imposing it is an inherently violent act. A lot of design is a form of technologically mediated violence. Getting people to do your bidding, however well intended. Which given my own vocation and work in the past is a kind of troubling thought to arrive at… Help?
Sebastian makes his best point on slides 113–114. Ethical design isn’t about doing the least harm, but about doing the most good. And, to come back to my Twitter rant, for me the ultimate good is for others to be free. Hence non-prescriptive design.