This excellent article is a concrete example what will happen if we don't be really careful. Also consider following the link to "ExtensionData Selfie".

I'm already a partial outcast in one of my bands because I don't use WhatsApp (where FB has openly lied to us with respect to data sharing).

https://thebolditalic.com/facebook-goes-full-black-mirror-how-facebook-is-making-membership-a-prerequisite-to-everyday-e88fb03b0eb9