SUBTERFUGUE motivation The primary goal of SUBTERFUGUE is to help you keep control of your computer. It can do this not only by flagging and blocking errant application behavior, but also by allowing you to subvert the goals of the application in a more general way by controlling its reality. It's not meant as a replacement for using free software, which is a key way for you to maintain control of your computer, but it can help you to detect perfidy and regain control over any software, free or not.