"No shady privacy policies or back doors for advertisers" proclaims the Firefox homepage, but that's no longer true in Firefox 128.
Less than a month after acquiring the AdTech company Anonym, Mozilla has added special software co-authored by Meta and built for the advertising industry directly to the latest release
Here, specifically: https://lemmy.zip/post/19194792
Also: A Word About Private Attribution in Firefox, by the Firefox CTO.