Once your data is shared with third parties, you lose control over how it is used, retained, or further shared, and those parties operate under their own privacy policies which may provide fewer protections.
Meta's policy authorizes collection of an exceptionally broad range of personal data — including location, biometric features, financial information, browsing history across third-party sites, and sensitive inferences about health and political views — primarily to serve targeted advertising. Non-users who have never created a Meta account are also subject to data collection when they visit sites using Meta's tracking tools such as the Meta Pixel. You can review and limit off-platform tracking by visiting Facebook Settings > Your Facebook Information > Off-Facebook Activity and clearing or restricting that data.