Why can I port my posts but not the profile platforms built from watching me?

GDPR Article 20 gives you the right to take your data to a new service, but it explicitly excludes inferred and derived data. The preference scores, behavioral segments, attention graphs, and interest models that recommendation platforms build from years of your activity stay with the incumbent when you leave. A 2024 Computer Law and Security Review study found this asymmetry is structurally entrenching: a competitor who receives your raw data still has to rebuild years of signal from scratch while the incumbent retains the refined interpretation. A 2025 arXiv study on recommender profile portability confirmed that even when raw interaction histories transfer between services, recommendation quality does not follow.