Companies are profiling you from your smartphone use - how to stop them

Companies can collect more about you from smartphone activity than you might expect. Every search, website visit, purchase, social post or location ping generates signals that, over time and across services, are stitched into a detailed shadow profile.

Those profiles may link personally identifiable information, device identifiers, contacts, purchase history, income estimates, interests, health and fitness logs and app telemetry. Browser queries, online purchases, social media engagement, app usage and subscription activity each add signals; advertising IDs and cross-service tracking can tie those signals together. "The biggest risk is aggregation," Yasir Zahid, head of business security at Secure.com told ZDNET.

To reduce profiling, audit app and smartphone permissions to limit what your handset shares, and review ad-personalization and privacy settings to curb the flow of data between your devices, marketers, brokers and other third parties.

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