About CNAME tracker:
Update (2021-03-16): Many people now know AdGuard published CNAME tracker lists. As I wrote below, one should note even without such lists or CNAME uncloaking EasyPrivacy already blocked at least 70% of CNAME tracker all over the world. From the perspective of a filter author, CNAME tracker is no different from other tracker - we inspect script or request and if it sends unnecessary user data we block it unless doing so causes trouble. In fact, I was the first one opened an issue in the AdGuard's CNAME tracker repository to expand its coverage - some of CNAME tracker I proposed were not blocked not only by AdGuard but also by other services such as NextDNS because the trackers were unknown to them. CNAME uncloaking is done by checking the tracker's canonical name in known tracker database so is helpless against unknown tracker, and there are always such trackers out there.
I really don't understand why it's so special to some people. Apparently they still believe subscribing a dedicated anti CNAME tracker list is mandatory to block them if a DNS-level blocker is not deployed on an other layer. The fact is EasyPrivacy alone, or the combination of AdGuard Tracking Protection and my list, blocks about
70% of CNAME tracker while DEFINITELY many other analytics and trackers have slipped whatever your lists through, as long as you visit many sites. You prefer to double-lock a window and keep the door open? CNAME tracker is NOT at all harder to block and filter authors know much more serious circumvention. Of note, Google provides
Server-side Tagging as
announced in early 2020. This utilizes A or AAAA record, which is very well expected at the time of the CNAME fuss1. It's weird those who made fuss about CNAME cloaking seem to be silent about this. All these remind me that many people keep NoCoin despite EasyPrivacy + uBlock filters - Resource abuse covers 99% of them, and that others keep Adblock Warning Removal with a completely wrong assumption it has something to do with anti-adblock wall. Don't be fooled by misinformation on the Internet.