But that should only help e.g. a web store to track you from the ad you clicked, which seems reasonable.
It should not allow e.g. Facebook to link your activity on a news site to your Facecbook cookie, because while you're on cnn.com, your browser is using the cnn.com-specific cookie jar for everything, including the like button?
Sorry another of my articles in french: https://pixeldetracking.com/fr/les-signaux-resilients-de-fac..., but Facebook is making it easy to integrate their "Conversion API (CAPI)" with GTM Server-Side tagging