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

This ZDNET guide explains how advertisers and data brokers collect and aggregate signals from smartphones and online activity to build detailed "shadow profiles" used for targeted advertising; it enumerates data sources (browser activity, purchases, social media, apps, subscription services), explains cross-service tracking mechanisms (advertising IDs, cookies, device fingerprinting), and provides practical privacy recommendations (audit app permissions, disable personalized ads, remove advertising ID, use secure browsers and VPNs, create a junk email, delete unused apps, consider data removal services).