CJEU-C-251/21 Meta Platforms and Others v Bundeskartellamt
Just a snippet
"Furthermore, the CJEU held that where the user of an online social network visits websites or apps to which one or more of the categories set out in Article 9(1) GDPR relate, the user does not 'manifestly make public', within the meaning of Article 9(2)(e) GDPR, the data relating to those visits collected by the operator of that online social network via cookies or similar storage technologies."
https://gdprhub.eu/index.php?title=CJEU_-_C-252/21_-_Meta_Platforms_and_Others_v_Bundeskartellamt