There is an idea that I saw (I believe it was an HN comment some years ago) that would massively help privacy in the smartphone age. For every set of permission

There is an idea that I saw (I believe it was an HN comment some years ago) that would massively help privacy in the smartphone age. For every set of permissions an app requests, you can choose to allow or deny these permissions (as currently possible) or there would be a third option: provide a false set of data that imitates the data normally requested. e.g., instead of providing camera permission, the false data would return a black image with your camera resolution, and the app would function normally except that pictures would not appear. I believe that this would be an insanely useful feature. I know that I would use it quite a lot. It kind of reminds me of the secret codes that they show in spy movies- there is an authentication word that spies normally use when communicating with a contact, and a second alternative authentication word they can use when they are under duress (third party coercion) and need the contact to know this but interact under the guise that authentication proceeded as normal.