TikTok

One of the broadest collection regimes of any consumer app — including biometrics, keystroke patterns, and content you record but never publish.

Data flows to ByteDance affiliates, advertisers, measurement partners, and independent researchers — with limited transparency on what goes where.

Some in-app controls exist, but Do Not Track is ignored, opting out may break the app, and there are no specific data retention timelines.

Vague 'reasonable measures' security with no certifications disclosed, AI training on your content, and policy changes communicated only by updating a date.