Your phone is sharing data without your knowledge – how to stop it ASAP
Elyse Betters Picaro / ZDNET Follow ZDNET: Add us as a preferred source on Google. ZDNET’s key takeaways Your phone may be sharing data without your awareness. Certain data sharing is necessary, but some can affect your privacy. Review and block any unnecessary app permissions and data access. You may think that your smartphone falls…
Follow ZDNET: Add us as a preferred source on Google.
ZDNET’s key takeaways
- Your phone may be sharing data without your awareness.
- Certain data sharing is necessary, but some can affect your privacy.
- Review and block any unnecessary app permissions and data access.
You may think that your smartphone falls asleep and remains inactive during the night when you’re in bed and not using it for hours. But that’s not the case. Your phone takes advantage of this downtime to share bits of data with the device’s manufacturer and other parties. And that could be both good and bad, according to NordVPN.
Also: The best data removal services of 2026: Delete yourself from the internet
Much of this information needs to be sent to the manufacturer to keep your device up to date and functioning properly. With that goal in mind, your phone might share any of the following tidbits:
- Device identifiers such as IMEI numbers, hardware serial numbers, and SIM details
- Telemetry data about the device’s system status or health
- Service checks for push notifications and operating system updates
- Crash logs or diagnostic analytics
- The connectivity state, such as Wi-Fi vs. mobile
- Content updates, including news, social feeds, and synced emails
“The above are legitimate reasons for idle data transmissions,” NordVPN CTO Marijus Briedis said in a news release. “It’s needed for system health reporting, operating system update availability checks, network and connectivity management, and content synchronization for email and messages.”
But then there’s other shared data not considered essential that could infringe on your privacy. These can include any of the following:
- Persistent identifiers. Device IDs and advertising IDs for mobile apps can be transmitted even though they aren’t needed to keep your phone operating. Instead, such IDs allow companies and advertisers to track and link your activity across their apps and services. Armed with this information, these parties can build behavioral profiles and track you even when you’re not using an app.
- Location-related signals. Even if precise GPS is disabled, your phone could still share general location data, Wi-Fi and Bluetooth identifiers, and local network data. These signals can enable device makers and others to detect your overall movements and locations.
- Background analytics and diagnostics. Your phone could be sharing analytics and telemetry data even when you’re not using it. With these analytics, a third party can learn how and when you use an app, determine when specific system events occur, and even find certain behavioral patterns.
Whether sent to your device maker or to advertisers and other third parties, certain data is being shared without your knowledge or permission. The ultimate goal is to build a profile based on your actions and activities, allowing companies to target you with more relevant, but often intrusive, advertising.
Also:Best VPN services 2026: Our top picks for speed and security
“From a cybersecurity standpoint, unnecessary background data sharing is not just a privacy issue — it’s a risk multiplier,” Briedis added. “Each identifier or telemetry signal adds another piece to a much larger puzzle. When combined, these data points can reveal sensitive behavioral patterns and expose users to tracking, profiling, or interception, often without their knowledge.”
Tips for protecting your privacy
Though you can’t block all types of data from being shared, nor should you, you can limit the exposure of certain information that threatens your privacy. Toward that end, Briedis offers the following tips:
- Review any unnecessary permissions granted to your apps. Pay attention to any apps that track your location, scoop up background data, have access to the microphone or camera, or can view your photo library.
- Review background app refreshes. Most apps don’t need background refreshes, so you’ll want to manage this setting. To do that on an iPhone, go to Settings, select General, and then tap Background App Refresh. On an Android device, head to Settings, select Apps, and then open each app. Select the setting for Permission to view any existing ones. Tap a specific permission to disable it.
- Restrict cloud backups. Turn off auto-sync for any data you don’t need backed up from your device. Alternatively, make sure your cloud-based backups are secured with a password.
- Disable personalized ads. To limit tracking for advertising purposes, turn off the option for personalized ads on your device. On an iPhone, go to Settings, select Privacy & Security, tap Apple Advertising, and then turn off the switch for Personalized Ads. On Android, go to Settings, select Security & Privacy, tap Privacy Control, and then select Ads. From there, you can customize the ad topics you see and reset or delete your advertising ID.
- Use a VPN. Consider using a VPN on your mobile device. Beyond protecting you from websites that aim to track you, such a tool can also reduce the amount of profiling performed by advertisers.
