Ideally a user would never have to make a trust decision. However, if there is no admin available to make a trust decision for the user, & the user wants to be able to use an application that needs high trust, the only one that can make the decision is the user. The challenge is to help users make the right decisions. Users make implicit trust decisions all the time. Putting a CD into a computer, buying a book online & installing an application are implicit trust decisions that users make today. By prompting to install or run application upfront, we are trying to leverage that implicit trust decision that is made by installing an application.