Mozilla is doing a ton to ensure that people know they are all about privacy and security with the latest release of Firefox.
...we believe that privacy is fundamental to a healthy internet. That’s why we build Firefox, and all our products, to give you greater control over the information you share online and the information you share with us. We strive to collect only what we need to improve Firefox for everyone.
To enable tracking protection, open preferences and click on "Privacy & Security," then scroll down to "Tracking Protection" and change that setting to "Always." 😎
A page you may not know about is Mozilla's full-disclosure privacy page for Firefox that includes explanations and details on what data Firefox shares and how you can change your settings to share even less. This page is auto-opened when you first install and launch Firefox.