> But how do we abstract other resources like cameras, keys, contacts, network ports, or money? Android has some of that figured out. For instance, instead of

> But how do we abstract other resources like cameras, keys, contacts, network ports, or money? Android has some of that figured out. For instance, instead of getting a permission to use the camera directly, an application can use a camera intent, which will pop up the camera application (which does have that permission); when the user takes the picture, the original application will receive something somewhat similar to a capability which can be used to access that picture (and only that picture). The same idea can easily be extended to contacts (use an intent which pops up the contacts application, which then return something somewhat similar to a capability to access the contact chosen by the user), and so on.