Mozilla with Firefox positions itself as a user privacy focused company but it looks like this is changing, having recently acquired an advertising tech company itself.
And following that acquisition it has sneaked in an opt-out piece of tracking into the latest Firefox version.
Under “Privacy & Security” in settings you will find a “Web Site Advertising Preferences” section with the option enabled by default.
Clearly the next step you need to be doing if you are a user of Firefox is to disable this option.
Further details and analysis of this can be found at the privacyguides.org site.
https://blog.privacyguides.org/2024/07/14/mozilla-disappoints-us-yet-again-2/