- set up a new empty site, listed absolutely nowhere, on quite dedicated hosting.
- open it in Chrome.
- a couple minutes later, observe Googlebot appearing in the visitor logs of the site.
Lastly, if you go to the ‘My activity’ settings on Google, you can see: “Include Chrome history and activity from sites, apps, and devices that use Google services”, which I guess can still be dissected further. And I have some website visits from 2016 listed there: including Wikipedia, which doesn't seem to use Google Analytics currently (not sure about 2016)—though these could be visits through Google search.
Also, text in the linked tweet directly says that Google tracks users on third-party sites through Chrome.
The statement that Chrome does not honour the networking stack's DNS settings does not agree with my observational data. I run pi-hole DNS and Chrome absolutely fails to load domains blacklisted there.
Settings > search for Use secure DNS for DNS-over-TLS.
Cross-device sync of passwords, autofills, bookmarks, history, open tabs
Ads: https://support.google.com/ads/answer/2662856#zippy=,when-yo...
Analytics: https://support.google.com/analytics/answer/9445345?hl=en&re...
tl;dr If logged in to Chrome, your Google Account can be used as an "identity signal" in place of a first-party cookie. This allows cross-domain and cross-device tracking.
I’m pretty sure it does not track any activity on non-Google properties.
Can't remember, though, if it's always encrypted, or just optionally encrypted.