Your smartphone knows where you are, where you've been, and where you're likely going next. Dozens of apps collect this information — often in the background — and sell it to a data broker ecosystem most people have never heard of. Here's the complete picture.
Modern smartphones use multiple location technologies simultaneously, triangulating from different signals to produce a location estimate that is accurate to within a few meters in optimal conditions. The technologies are layered — the phone uses whichever signals are available and combines them for the best accuracy.
Your phone scans for nearby Wi-Fi networks constantly — not to connect to them, but to use their signals for location purposes. This means your phone's location can be determined by Wi-Fi even when you're not connected to any network and even when your phone's Wi-Fi is set to "off" on some devices. Google and Apple maintain global databases mapping Wi-Fi network identifiers to physical locations, built from years of mobile device location data. Source: Federal Trade Commission.
When you grant an app location access, you're not just enabling a feature — you're potentially enabling ongoing data collection that continues in the background and extends well beyond the app's core function. Location data has multiple revenue applications:
Some of the most aggressive location data collectors are apps with no obvious reason to need precise location history — weather apps, coupon apps, simple games. These apps request location access to enable a minor feature while collecting detailed movement history as their primary business. A weather app that records your precise location every 15 minutes and sells that data to brokers is not unusual. Always consider why an app needs precise, always-on location access before granting it. Source: FTC Mobile Privacy Report.
Location data flows from apps to a specialized layer of data brokers who aggregate, enrich, and resell it. Companies like Veraset, SafeGraph, Foursquare, and numerous others collect precise movement data from millions of smartphones — derived from app SDKs embedded in popular apps — and package it for sale to advertisers, analytics companies, hedge funds, and government agencies.
The FTC has pursued enforcement actions against several data brokers for selling sensitive location data — specifically, data revealing visits to medical clinics, places of worship, and political events. This enforcement reflects growing regulatory concern about the sensitivity of precise location data and its potential for misuse. Source: Federal Trade Commission.
Both iOS and Android distinguish between two primary location permission levels for apps:
The vast majority of apps have no legitimate need for "Always" location access. Navigation apps that provide turn-by-turn directions need it while navigating. Most other apps — weather, social media, retail, games — function perfectly with "While Using" access, and the "Always" request is primarily for data collection purposes.
Both iOS and Android provide tools to review and adjust location permissions for every app on your phone.
On iPhone (iOS): Go to Settings → Privacy & Security → Location Services. You'll see every app on your device and its current location permission setting. For each app, you can choose: Never, Ask Next Time, While Using the App, or Always. You can also toggle "Precise Location" on or off separately from the permission level.
On Android: Go to Settings → Location → App Permissions (or Privacy → Permission Manager → Location depending on Android version and manufacturer). You'll see all apps organized by permission level — "Allow all the time," "Allow only while using," "Ask every time," and "Don't allow."
A reasonable default is to grant "While Using" permission to any app that legitimately needs location, and "Never" to any app that you don't believe needs it at all. Almost no consumer app needs "Always" location access — including most navigation apps, which can access location when opened. Review your location permissions list and downgrade any "Always" permissions to "While Using" as a baseline. Most apps won't even notice the change.
Both iOS 14+ and recent Android versions allow you to grant approximate location access rather than precise location — sharing your general area (roughly neighborhood or city level) rather than your exact GPS coordinates. For apps that don't need pinpoint precision — most weather, news, and local service apps — approximate location provides the feature while meaningfully limiting the specificity of data that can be collected.
Your phone's location tracking capability is sophisticated, continuous, and largely invisible in normal use. Apps collect this data not just to provide features but as a revenue stream — selling your movement history to brokers who aggregate, enrich, and resell it to advertisers, analytics firms, and in some cases government agencies. The controls exist on both iOS and Android — they're just not turned on by default. Auditing your location permissions, defaulting to "While Using" rather than "Always," and using approximate location where possible are practical steps that meaningfully limit what's collected without affecting the features you actually use. Source: Federal Trade Commission Mobile Privacy Report.