How Apps Use Your Photos to Track Your Location

source: lifehacker.com by Nick Douglas

Well she sneaks around the world from Kiev to Carolina

If you’re worried about apps tracking your location, it’s not enough to limit your location sharing. You need to limit camera-roll sharing too. If you’ve ever given an app access to your camera roll—to take photos, or store screenshots, or any given reason—you’ve also let it see where all those photos were taken. Felix Krause, an iOS developer and security writer, built an app to demonstrate this back door:

📍 Any app gets complete access to where you've been the last years within a second, when you grant access to photos https://t.co/cLAMzibRrj pic.twitter.com/vRaUxdAxds

— Felix Krause (@KrauseFx) September 27, 2017

 Krause’s iOS app DetectLocations shows you just how much apps can learn about your past (and future) location through your photos’ EXIF data. Grant it camera access and it will show you where you took all your photos, whether you were in a vehicle when you took them, and your likely routes between each photo location.

You can limit access to past photo data by moving everything out of your camera roll before you grant an app permission. But that won’t stop an app from spying on any photos going forward.
If that freaks you out, you can prevent this by disabling geotagging on your photos. As we explained in 2014, Android users can turn off geotagging in their camera settings; iOS users can turn it off in their privacy settings. Of course, then you won’t be able to make photo maps. There’s no granular setting to disable geotagging for third-party apps.
Krause’s iOS app DetectLocations shows you just how much apps can learn about your past (and future) location through your photos’ EXIF data. Grant it camera access and it will show you where you took all your photos, whether you were in a vehicle when you took them, and your likely routes between each photo location.

You can limit access to past photo data by moving everything out of your camera roll before you grant an app permission. But that won’t stop an app from spying on any photos going forward.
If that freaks you out, you can prevent this by disabling geotagging on your photos. As we explained in 2014, Android users can turn off geotagging in their camera settings; iOS users can turn it off in their privacy settings. Of course, then you won’t be able to make photo maps. There’s no granular setting to disable geotagging for third-party apps.