reCAPTCHA – owned by Google

Extra verification, many websites depend on reCAPTCHA. In 2009 this services is acquired by Google. Wikipedia states:

The current iteration of the system has been criticized for its reliance on tracking cookies and promotion of vendor lock-in with Google services; administrators are encouraged to include reCAPTCHA tracking code in all pages of their website to analyze the behavior and “risk” of users, which determines the level of friction presented when a reCAPTCHA prompt is used. Google stated in its privacy policy that user data collected in this manner is not used for personalized advertising. It was also discovered that the system favors those who have an active Google account login, and displays a higher risk towards those using anonymizing proxies and VPN services.

https://en.wikipedia.org/wiki/ReCAPTCHA

In my opinion this service should be open-source software code. Not used by tracking companies to restrict acces to a website if not used. So no gstatic.com no google.com no googleapis.com. In the above screenshot the reCAPTCHA can only be submitted if allowed to use:

2 cookies, 2 from google.com.
20 Cascading Style Sheets (or CSS), 12 from google.com, 1 from googleapis.com and 7 from gstatic.com (gstatic is also part of Google); a style sheet language used for describing the presentation of a document written in a markup language like HTML. Privacy infringement: it allowed websites to uncover a user’s browsing history and figure out what sites the user had visited. Combined with other Web technology such as JavaScript or simply loading of background images, lets Web pages determine whether a URL is in the user’s history very quickly and without any interaction from the user. This is mitigated by browsers.
6 images, an (leaky) image can reveal whether the user is visiting a specific website. None from third-party sources.