https://mazech.com/2019/08/facebook-google-and-oracle-cloud-are-tracking-the-porn-you-watch-in-private/ :
The study found that Google and its various outlets had trackers on 74% of the web’s top online orgasm destinations, Oracle had 24% and Facebook 10%.

And if you think you’re being smart by browsing through “incognito” mode, well you got it wrong. Even when such browsing sessions aren’t stored in your browser history, the data is still transferred to these third parties.