I really detest that principle. For the design of my software I make almost every action reversible and avoid at all costs confirmation dialogs or anything that

I really detest that principle. For the design of my software I make almost every action reversible and avoid at all costs confirmation dialogs or anything that makes it seem like the user could be at fault for something if they choose incorrectly. I also work on financial trading software so I do need to think a great deal about user error and the best principle I have found is to never create a situation where a confirmation is needed. Among new users it creates anxiety and indecisiveness, and among experienced users they just ignore it and it's noise to them. All confirmation dialogs do is make the developer/designer punt responsibility off to the user for what is generally a bad design decision.