The trackers still exist, even though Tracking Protection is enabled. So Ghostery is taking credit for the trackers, even though they would already be blocked by Tracking Protection. Also, Ghostery uses a different blocker list, so it may block things that Tracking Protection doesn't block

That's a good hunch. But I think to have a definitive answer we would need to get a Firefox developer to explain the order of evaluation of Tracking Protection and ad blockers addons. Also, as Ghostery is a Firefox endorsed addon, it would be good to know from an official source the overlap of both tools for blocking trackers.

It's not a hunch, that's what's happening.

Thanks Tyler. I am a fairly technical person, could you please ellaborate a bit more? I would expect Tracking Protection to block all trackers to the extent that Ghostry would not even be aware of them.

Why would you expect that? And even if that did happen, ghostery can still see the trackers, so nothing is blocking it from saying it blocked them. On top of that, TP and ghostery use different blocklists, so why do you expect them to be the same?

HI, that is not going to happen regarding Developers.

Mozilla ok's Extensions after being tested with Firefox and does not endorse any Extension/add-on it supplies a website page https://addons.mozilla.org/en-GB/firefox/addon/ghostery/ for them to distribute their Extension/add-on/Theme/Dictionary from. They have a Homepage https://www.ghostery.com/ and a support page https://ghostery.zendesk.com/hc/en-us and Support Contact support@ghostery.com listed as does all other Extensions Developers submit. Please enjoy the publicly available information as Firefox is Open Source Software.

• https://wiki.mozilla.org/Security/Tracking_protection
• https://wiki.mozilla.org/Services/TrackingProtection
• https://wiki.mozilla.org/Security/Safe_Browsing
• https://blog.mozilla.org/firefox/files/2017/09/tracking-protection-test.pdf
• https://wiki.mozilla.org/Security/Fusion
• https://en.wikipedia.org/wiki/Firefox_Focus

Please let us know if this solved your issue or if need further assistance.

@Tyler Downer - Fair question. I think it depends on the order that Firefox evaluates websites using Tracking Protection and add blockers. Hence my original question.

I would expect Tracking Protection to serve as a filter by blocking HTTP requests to blacklisted URLs found on disconnect.me, on top of that Ghostry would do the same. So, in that filtering order Ghostry would not even be aware of the vast majority of trackers - which as I observed is not the case.

@Pkshadow - Thank you for your kind reply. However, I fully disagree with you. If you go to the Add Ons menu of Firefox you will read the following:

There are thousands of free add-ons, created by developers all over the world, that you can install to personalise your Firefox. From fun visual themes to powerful tools that make browsing faster and safer, add-ons make your browser yours. To help you get started, here are some we recommend for their stand-out performance and functionality. The highlighting was done on my part, but it is explicitly clear that Mozilla is recommending Add Ons to Firefox users. The only reason I have Ghostry installed is because Mozilla is recommending it.

I think that extensions (Ghostery) are the first to block content and TP gets active at a later time after Ghostery has done its job, so when all items already have been blocked by Ghostery then there is nothing left for TP. Firefox shows messages in the Web Console then content is blocked by TP, so you can check the console with Ghostery enabled and with Ghostery disabled.

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en/Tools/Web_Console

Cor-el, you nailed it! Thanks for the solution!