How do I turn on the Do Not Track feature? can help explain what do not track is and isn't.

See also:

• https://blog.mozilla.org/privacy/2011/11/15/deeper-discussion-of-our-decision-on-dnt-defaults/

"Tell sites I do not want to be tracked" = DNT bit is set to 1

"Tell sites that I want to be tracked" = DNT bit is set to 0

"Do not tell sites anything about my tracking preferences." = No DNT information in the browser header

Firefox's implementation seems odd to me, instead of taking the True/False route as the other browsers have, they chose to add the option to explicitly choose to be tracked. In my mind, not telling the site anything is the same thing, and only serves to make determining DNT programmatically harder. Take for instance the tutorial code here: https://developer.mozilla.org/en-US/docs/The_Do_Not_Track_Field_Guide/Tutorials/2_Displaying_DNT_status_with_caching That code doesn't attempt to determine the 'value' of the DNT header just that one exists. So both DNT:0 and DNT:1 == true (with that code) when DNT:0 should be an explicit opt out. It is my opinion that by needlessly adding the option for DNT:0 (yes I know w3 et. al. are still trying to figure out "exactly" what DNT:0 does) since it's not a standard yet and no one knows exactly what it is intended to do (besides adding another layer to what should be an basic on/off switch) I think it serves to lull users into a false sense of security. I'm not knocking Mozillas part in the DNT issue and I'm glad you're taking it on. But a true/false approach ('Explicit DNT' / 'I don't Care') seems better perhaps just change the label or offer only a radio button (ala chrome) that says 'Don't allow websites to track me' (DNT:1) or unticked no DNT header at all.

@taneis To answer more your original question and for posterity, The default "Do not tell sites anything about my tracking preferences." does not set a DNT bit in the header (see my above post). This means that any site that is going to actually respect the DNT header in your browser will assume (rightly) there is no DNT settings in your browser and will continue to track. To the contrary if "Tell sites I do not want to be tracked" is set then a DNT value of 1 is included in your header. See above for my thoughts on DNT:0 "Tell sites I do not want to be tracked" . Now here's the rub. Websites don't have to do anything with this information (except in CA as of Jan 1 2014). So it's really arbitrary. In theory the way it should work is your browser sends the bit and as these headers make their way to the third parties Google Analytics included the third party stops whatever tracking they're doing...well we all know how advertisers roll. So it's really up to the third parties to respect this. Now the California angle is interesting because it's asking ALL website owners to disclose what they are doing when they receive this information...So for instance myself who uses google analytics on my sites now have to either a. trust that google (or other ad agencies if I used them) are going to respect MY users decision or b. It's up to me to thwart

I chose B. When my sites detect DNT:1, I intercept any third party scripts (Google Analytics) from executing before the page even renders. This way I don't have to rely on third parties from complying at all and the potential backlash because the user WAS technically on MY site.

hth

-jb

We have to have 3 options to comply with the laws in certain regions of the world (Such as the EU) and it's easier to just have 1 uniform interface than 2-3 different implementations.

@Tylerdowner

Wow, thanks for the heads up I was unaware that it was mandatory in other countries to have the DNT:0 option. Curious that Chrome et. al. aren't utilizing that option - I would imagine it's Mozilla being more forward thinking and adherent to the actual 'standard'.

Can you explain a bit more on the logic of their decision for adopting that (EU), from what I can tell could add another layer as sort of a "I really don't care hit me with anything" D:0 and "Certain third parties can send certain types of info" no DNT to people with no setting...does that sound about right? I can kinda get that logic...as a way to appease advertisers or developers who track internally. It makes sense in the sense of internal Google Analytics