Ways Technology Quietly Collects Data in the Background

Your phone's GPS chip can pinpoint your position with high accuracy, but location data is also gathered through nearby Wi-Fi networks and cell towers — even when GPS is turned off. Many apps request location access to function (maps, weather), but others — like shopping or social apps — may request it for advertising purposes. On most devices, you can set location permissions to "only while using the app" rather than granting constant background access.

Apps routinely record how you interact with them: which screens you visit, how long you linger, what you tap, and when you close the app. This telemetry (data sent back to the app's developers) is used to improve design and, in many cases, to build a profile of your interests. This kind of logging is usually disclosed somewhere in a privacy policy, though those documents are rarely easy reading.

Websites place small files called cookies on your device to remember your preferences and login status — that's the helpful version. A separate category, known as third-party tracking cookies, follows you across different websites and builds a picture of your browsing habits. Tracking pixels — tiny invisible images embedded in emails or web pages — can record when you open a message or load a page. Modern browsers offer settings to block or limit both.

Many apps request microphone or camera permissions to enable features like voice search or video calls. However, once granted, those permissions may remain active in the background. Operating systems on both iOS and Android now show visual indicators (a colored dot or icon) when the microphone or camera is in use, and privacy dashboards log recent access. If an app has microphone access and you're unsure why, it's worth revoking it and checking whether the app still functions as needed.

Every device has unique identifiers — strings of numbers used to distinguish it from others on a network. Advertisers and analytics companies use these, along with a technique called browser fingerprinting, to recognize your device even without cookies. Fingerprinting works by combining details like your screen resolution, installed fonts, browser version, and time zone into a profile that is often unique enough to identify your device reliably across sessions.

Smart speakers and voice-enabled devices are designed to listen for a wake word — "Hey Siri," "Alexa," or similar — at all times. This requires the device to process ambient audio continuously. Most manufacturers say only the audio following the wake word is sent to their servers, but independent researchers have documented instances of accidental activations. You can review and delete stored voice recordings through most platform settings, and many devices include a physical mute switch for the microphone.

When you sign in to an app using "Sign in with Google" or "Sign in with Apple," data can flow between that app and the platform you used to authenticate. Similarly, services you subscribe to — streaming platforms, productivity apps — log your activity, preferences, and usage patterns as part of how they personalize their product. Our article on how streaming and app subscriptions actually work explains what you agree to when you sign up. Software updates can also adjust what data an app collects, which is one reason it's worth understanding what software updates actually change.