Even After Deleting Apps From Your Phone, This Is How They Can Still Secretly Stalk You Online

By now most of us are aware of just how much data app developers get from us. That's why both Android and iOS offer in-depth controls to block app permissions, even after you've already approved them. But what about apps that track you after you've uninstalled?

A recent report by Bloomberg Businessweek shows that a lot of developers are resorting to something called "uninstall tracking tools". Offered by companies like Adjust, AppsFlyer, MoEngage, Localytics, and ClaverTap, these let major companies like T-Mobile, Yelp and Spotify gather data from people that uninstall their apps, in order to find out why. Unfortunately, many smaller developers are also jumping on the bandwagon.

Think about it. If you've ever found yourself seeing ads for an app online after you've uninstalled it, that's a good indication the app is stalking you. After all, a customer lost is the perfect one to advertise you. The developers know you're interested in their product, maybe you'll be convinced to come back after an update that fixes things you didn't like.

Also Read: Over 3,300 Android Apps Are Spying On Kids, Tracking User Data Without Any Parent's Permission

The thing is, this sort of technique abuses a perfectly innocent feature of both Android and iOS: push notifications. These are the updates that tell you there's a new email or chat waiting for you. The thing is, in the background the developer is pinging your app at intervals to refresh the feed or whatever, which is how a notification reaches you as soon as the message does. When that happens, the app responds to the servers.

But if the app doesn't reply, it's logged as an uninstalled app, and the uninstall tracking tools log that change, as well as the mobile and the phone's unique advertising ID. Now, the developer has a way to pinpoint you as a newly lost user. For the most part, this tool is meant to gather data of what went wrong, without having to bother the user with surveys questions about why they uninstalled. Instead, these developers seem to just be going after them with refreshed ads.

This practice actually goes against the policies of both Apple and Google, which say silent push notifications can't be used to build an advertising database. However, the two companies failed to respond to a comment on the report. One can only hope that, if they didn't know about the practice, that they're going to crack down on it ASAP. Then again, it's still unclear just how they'd go about enforcing this.

In the meantime, the only way to avoid this is to disable ad personalization in your Google settings. This hides your unique advertising ID, so creepy apps can't harass you.