There has been a lot of research and development in the field of computational trust in the past decade. Much of it has acknowledged or claimed that trust is a good thing. We think it's time to look at the other side of the coin and ask the questions why is it good, what alternatives are there, where do they fit, and is our assumption always correct? We examine the need for an addressing of the concepts of Trust, Mistrust, and Distrust, how they interlink and how they affect what goes on around us and within the systems we create. Finally, we introduce the phenomenon of ‘Untrust,' which resides in the space between trusting and distrusting. We argue that the time is right, given the maturity and breadth of the field of research in trust, to consider how untrust, distrust and mistrust work, why they can be useful in and of themselves, and where they can shine.