The mental disconnect that occurs in a "limiting assumption" is an excellent opportunity for exploitation. This cognitive security hole makes it possible to identify opportunities for injecting "rootkits" into human-scale systems that won't be found by conventional thinking. Con-men and marketing professionals have already realized the importance of these techniques and use them to great effect. In this workshop, we'll work through a methodology called Axiomatic Design that exposes these assumptions. We will apply this and other techniques to design problems and develop an "assumption-hacker" toolkit that will let you spot and make use of these opportunities.