Do Not Track

 Do Not Track  (also known as DNT) is a technology and policy proposal that enables users to opt out of tracking by websites they do not visit, including analytics services, advertising networks, and social platforms.

Specifically, DNT allows a user to express their personal preference regarding tracking to each server and web application that they communicate with via HTTP, thereby allowing recipients of that preference to adjust tracking behavior accordingly or to reach a separate agreement with the user that satisfies all parties.

What can users do?
According to the W3C Tracking Preference Expression (DNT) spec, a user expresses their preference that they not be tracked by having their browser send an HTTP header  with each request. Most web browsers allow users to configure the  feature.


 * This post from 2017-01-09 contains HOWTOs for turning on DNT in the Firefox, Chrome, and Safari browsers on desktop and mobile.
 * Some privacy-oriented browser plugins such as the EFF's Privacy Badger also enable DNT as part of their anti-tracking behavior.
 * Use Firefox "Private Browsing" per https://blog.mozilla.org/blog/2017/11/20/firefox-private-browsing-vs-chrome-incognito/

What can sites do?
If a user has the DNT header set, sites could:
 * deactivate tracking/analytics scripts
 * hide embedded content from other sites behind click-throughs (examples: Adafruit, Medium)
 * A version of this is applied by DuckDuckGo, offering visitors the choice to either run the embed in place or visit the external video page (example: search result “indieweb youtube”).
 * Follow the EFF recommendations and declare your adherence to them using a  file

Dropping Support

 * Reddit is phasing out support throughout August 2017 and will no longer use DNT after that. They cite the lack of “buy-in from the entire ecosystem” (browsers and advertisers) as a reason for not supporting it themselves.

Articles

 * 2017-11-07 Mozilla Blog: Firefox Private Browsing vs. Chrome Incognito: Which is Faster? "In 2015, Firefox became the only browser to include Tracking Protection enabled by default in Private Browsing mode. Tracking Protection, as the name implies, blocks resources from loading if the URL being loaded is on a list of known trackers as defined by Disconnect’s Tracking Protection list. This list is a balanced approach to blocking and does not include sites that obey Do Not Track (as defined in the EFF guidelines)."