Firefox has been offering a "Do Not Track" option for quite a while (under Tools / Options / Privacy ). The problem is that websites were not required to honor that request.
Firefox has now added an new feature, called "Tracking PROTECTION", which uses a blocklist to actively block domains and sites that are known to track users.
For details --- including how to activate this feature --- see https://finance.yahoo.com/news/firefox-helps-cover-assets-latest-174857917.html

Windows 10 Pro (64-bit), Panda DOME 20, MBAM4 Pro, Windows Firewall, OpenDNS Family Shield, SpywareBlaster, MVPS HOSTS file, MBAE Premium, MCShield, WinPatrol PLUS, SAS (on-demand scanner), Zemana AntiLogger Free, Microsoft EDGE, Firefox, Pale Moon, uBlock Origin, CryptoPrevent.
[I believe computer-users who sandbox (Sandboxie) are acting prudently.]