We need to go even further for apps installed in mobile devices: We need to make it impossible for apps to determine that they've been denied a capability. Many useful apps refuse to run at all unless you give them access to personal information (e.g. your location) when there's no need for them to have such information to function. The solution is for the OS to spoof that capability by providing hostile apps with random data, or to otherwise fail to provide accurate data to the apps.

Of course a more ideal solution is for app stores to refuse to allow apps that list capabilities they cannot justify a need for, but at least in the Android world this doesn't seem to be happening.