In this paper, we examine a second dimension in which wearables challenge
existing threat models: they have the potential to secretly receive data or perform
computations in ways that confer an underhanded advantage to the user, such
as helping count cards in a casino or cheating on an exam. Although wearables
encompass a diverse range of form factors, we focus on smartwatches because
they are among the first feature-rich and programmable wearable devices to reach
a broad consumer audience.