Pathetic
So Mozilla finally implemented tracking protection, half a decade after IE did. And why now? Because their deal with Google has been not renewed, so they're not interested in enabling third parties to track their users anymore.
Actually, they are now counterinterested in enabling that. Instead, they want only themselves be able to track user behavior, so their own advertisements (called "Sponsored Tiles") stay relevant, while others' do not. That's the sole and only reason why they've implemented tracking protection.
So much about Firefox and a "better, open web", and keeping their "users first".
Thank god Firefox's market share is already down to barely above 10%, and most likely will sink to a few percent in the years coming.