My own experience bore that out. Using a box-fresh Google Pixel 6 Pro, I installed 36 popular free apps—some estimates claim people install around 40 apps on their phones—and logged into around half of them. These included the McDonald’s app, LinkedIn, Facebook, Amazon, and BBC Sounds. Then, with a preview of DuckDuckGo’s Android tracker blocking turned on, I left the phone alone for four days and didn’t use it at all. In 96 hours, 23 of these apps had made more than 630 tracking attempts in the background.
Using your phone on a daily basis—opening and interacting with apps—sees a lot more attempted tracking. When I opened the McDonald’s app, trackers from Adobe, cloud software firm New Relic, Google, emotion-tracking firm Apptentive, and mobile analytics company Kochava tried to collect data about me. Opening the eBay and Uber apps—but not logging into them—was enough to trigger Google trackers.
At the moment, the tracker blocker doesn’t show what data each tracker is trying to send, but Dolanjski says a future version will show what broad categories of information each commonly tries to access. He adds that in testing the company has found some trackers collecting exact GPS coordinates and email addresses.
The beta of App Tracking Protection for Android is limited. It doesn’t block trackers in all apps, and browsers aren’t included, as they may consider the websites people visit to be trackers themselves. In addition, DuckDuckGo says it has found some apps require tracking to be turned on to function; for this reason, it gives mobile games a pass. While the tool blocks Facebook trackers across other apps, it doesn’t support tracker-blocking in the Facebook app itself. In DuckDuckGo’s settings, you can whitelist any other apps that don’t function properly with App Tracking Protection turned on.
The introduction of App Tracking Protection for Android comes at a time when ATT has pushed advertisers to Android, while also benefiting Apple. “ATT meaningfully changed how advertisers are able to target ads on some platforms,” says Andy Taylor, vice president of research at performance marketing company Tinuiti. The company’s own ads data shows Facebook advertising on Android grew 86 percent in September, while iOS growth lagged behind at 12 percent. At the same time, Apple’s ad business has tripled its market share, according to an analysis from the Financial Times. Around 54 percent of people have chosen not to be tracked using ATT, data from mobile marketing analytics firm AppsFlyer shows.
DuckDuckGo’s system is unlikely to have an impact anywhere near that scale and is more of a blunt tool. Unlike Apple, the company doesn’t own the infrastructure—the phones people use or the underlying operating systems—to enforce wholesale changes. Each time an app wants to track you, iOS presents you with a question: Do you want this app to track you? When you opt out, your device transmits the IDFA sent to advertisers as a series of zeros—essentially preventing them from tracking you. DuckDuckGo doesn’t have this luxury; its privacy browser app is installed on your phone like any other from the Google Play Store.