Phones Should Have a 'Guest Lock' Feature
The author argues that smartphones need a system-level 'guest lock' to restrict access to the active app, preventing others from snooping when you hand over your phone. They also propose hiding photos from the camera roll with privileged viewing modes or sets. The piece highlights the lack of such basic privacy features in modern mobile OSes.
A really nice feature would be a hardware button triggering this mode!
- odo1242
Both Apple and Android have this feature preloaded. On Apple it’s called Guided Access and is three taps of the power button if enabled. On Android I’m not sure but I do know it exists (edit: it’s called App Pinning)
On iOS you can also disable specific actions and even select areas of the screen you want to disable touchscreen usage over.
- re-framer
I believe this works on Android in general, but I tried on GrapheneOS. Open the Settings app. Tap Security & Privacy > More security & privacy > App pinning. After that is enabled, if you want to pin an app, open it, swipe up into the recent-apps view, tap the icon of the app above the preview pane, and select "Pin".
The feature is buried a bit. I believe this is because it's more of a best-effort protection. The settings page itself says:
"When an app is pinned, the pinned app may open other apps and personal data may be accessible. If you want to securely share your device with someone, try using a guest user instead."
- seri4l
It's the kind of feature that would rub people the wrong way, whether it's a cop, a friend, or a stranger you want to show a funny video to.
To give a couple of examples, using this would be a bit like locking the glove box in front of traffic cops, or going around the house locking rooms when you have a guest.
The only way to make it socially acceptable would be to make it some sort of default (for example, requiring face id when switching apps, with pin/fingerprint as a backup), which will probably be an option as the lag and failure rate of face id or other owner-detection technologies improve.
- Planktonne
This feels like a social problem, not a technological one, and I am unconvinced that a technological solution will work here.
If the worry is that the cop you hand your phone to will take more access than you want, then attempting to limit that access is probably not going to work out the way you want.
A more effective solution would be better legal protections.
- lionpv7
Well, iOS does already. „Guided Access“ is exactly what you described.