Apps tracking your activity — even while you sleep — is a pervasive practice, including on Apple’s iPhone.
What can you do to limit some of it?
1) Conduct an app census.
In iOS 12, go to Settings, then Privacy, and turn off location services for apps that don’t really need it — especially the ones that asked to access it “always.” (This is key because apps will wake up periodically if you give them “always” location access.”)
Go through the same process for other sensitive information, such as contacts and health data — as well as access to your microphone and camera.
Even better: Just delete any apps you don’t use regularly.
2) Turn on “limit ad tracking.”
Go to Settings, then Privacy — and look all the way at the bottom under the heading “Advertising.” Turning on “limit ad tracking” won’t stop all this unwanted behavior, but it does put up a speed bump.
3) Get Disconnect’s free Privacy Pro for iOS.
This app tallies and limits many trackers, kind of like a tracker blocker you add to a Web browser — except for your entire phone. It might interfere with the function of some apps, but Privacy Pro’s makers try to strike a balance between privacy and functionality. (You don’t need to pay for the subscription version unless you also want a virtual private network, or VPN, to help keep your data secret from your Internet service provider.)
What about Android users? Samsung phone owners can download a version of Disconnect’s software called Pro Privacy and Performance for $25 from the Galaxy Apps store. The Android app isn’t available in the wider Play Store, due to restrictions by Google.
4) Turn off “background refresh” on apps.
Go to Settings, then General and then Background App Refresh. Switching off access for apps will prevent them from sending out data while you sleep at night but won’t necessarily stop them from sharing your data with third parties while you use their apps. (Manually force-closing apps won’t help stop tracking by apps that you’ve allowed background refresh access.)
5) Use Apple’s first-party apps.
Apple holds its own services, such as Photos and Maps, to a higher privacy standard than other apps. In most cases, it encrypts your data and tries to minimize collecting it in the first place.
Read more tech advice and analysis from Geoffrey A. Fowler: