Do Not Track

From Wikipedia, the free encyclopedia
(Redirected from Do not track)

Do Not Track (DNT) is a formerly official HTTP header field, designed to allow internet users to opt-out of tracking by websites—which includes the collection of data regarding a user's activity across multiple distinct contexts, and the retention, use, or sharing of data derived from that activity outside the context in which it occurred.

The Do Not Track header was originally proposed in 2009 by researchers Christopher Soghoian, Sid Stamm, and Dan Kaminsky.[1] Mozilla Firefox[2] became the first browser to implement the feature, while Internet Explorer,[3] Apple's Safari,[4] Opera[5] and Google Chrome[6] all later added support. Efforts to standardize Do Not Track by the W3C in the Tracking Preference Expression (DNT) Working Group reached only the Candidate Recommendation stage and ended in September 2018[7] due to insufficient deployment and support.[8][9]

DNT is not widely adopted by the industry, with companies citing the lack of legal mandates for its use, (see Do Not Track legislation) as well as unclear standards and guidelines for how websites are to interpret the header. Thus, critics purport that it is not guaranteed enabling DNT will actually have any effect at all.[10] The W3C disbanded its DNT working group in January 2019, citing insufficient support and adoption.[11] Apple discontinued support for DNT the following month, citing browser fingerprinting concerns.[12][13] As of March 2023, Mozilla Firefox continues to support DNT, where it is turned on by default in private browsing mode and optional in regular mode.[14]

In 2020, a coalition of US-based internet companies announced the Global Privacy Control[15] header that spiritually succeeds Do Not Track header. The creators hope that this new header will meet the definition of "user-enabled global privacy controls" defined by the California Consumer Privacy Act (CCPA) and European General Data Protection Regulation (GDPR).[15] In this case, the new header would be automatically strengthened by existing laws and companies would be required to honor it.[16]


The DNT header accepts three values: 1 in case the user does not want to be tracked (opt out), 0 in case the user consents to being tracked (opt in), or null (no header sent) if the user has not expressed a preference. The default behavior required by the standard is not to send the header unless the user enables the setting via their browser or their choice is implied by use of that specific browser.[17]


In 2007, several consumer advocacy groups asked the U.S. Federal Trade Commission to create a Do Not Track list for online advertising. The proposal would have required that online advertisers submit their information to the FTC, which would compile a machine-readable list of the domain names used by those companies to place cookies or otherwise track consumers.[18]

In July 2009, researchers Christopher Soghoian and Sid Stamm created a prototype add-on for the Firefox web browser, implementing support for the Do Not Track header. Stamm was, at the time, a privacy engineer at Mozilla, while Soghoian soon afterward started working at the FTC.[19] One year later, during a U.S. Senate privacy hearing, FTC Chairman Jon Leibowitz told the Senate Commerce Committee that the commission was exploring the idea of proposing a "do-not-track" list.[20]

In December 2010, the FTC issued a privacy report that called for a "do not track" system that would enable people to avoid having their actions being monitored online.[21]

One week later, Microsoft announced that its next browser would include support for Tracking Protection Lists that block tracking of consumers using blacklists supplied by third parties.[22] In January 2011, Mozilla announced that its Firefox browser would soon provide a Do Not Track solution, via a browser header.[2] Microsoft's Internet Explorer 9,[23] Apple's Safari,[4] Opera[5] and Google Chrome[6] all later added support for the header approach.

In August 2015 a coalition of privacy groups led by the Electronic Frontier Foundation using W3C's Tracking Preference Expression (DNT) standard proposed that "Do not track" be the goal for advocates to demand of businesses.[24]

In January 2019, the W3C Tracking Protection Working Group was disbanded, citing "insufficient deployment of these extensions" and lack of "indications of planned support among user agents, third parties, and the ecosystem at large."[11][12] Beginning the following month, Apple removed DNT support from Safari, citing that it could be used as a "fingerprinting variable" for tracking.[13]

Internet Explorer 10 default setting controversy[edit]

When using the "Express" settings upon installation, a Do Not Track option is enabled by default for Internet Explorer 10 and Windows 8.[25] Microsoft faced criticism for its decision to enable Do Not Track by default[26] from advertising companies, who say that use of the Do Not Track header should be a choice made by the user and must not be automatically enabled. The companies also said that this decision would violate the Digital Advertising Alliance's agreement with the U.S. government to honor a Do Not Track system, because the coalition said it would only honor such a system if it were not enabled by default by web browsers.[27] A Microsoft spokesperson defended its decision however, stating that users would prefer a web browser that automatically respected their privacy.[28]

On September 7, 2012, Roy Fielding, an author of the Do Not Track standard, committed a patch to the source code of the Apache HTTP Server, which would make the server explicitly ignore any use of the Do Not Track header by users of Internet Explorer 10. Fielding wrote that Microsoft's decision "deliberately violates" the Do Not Track specification because it "does not protect anyone's privacy unless the recipients believe it was set by a real human being, with a real preference for privacy over personalization". The Do Not Track specification did not explicitly mandate that the use of Do Not Track actually be a choice until after the feature was implemented in Internet Explorer 10.[29] According to Fielding, Microsoft knew its Do Not Track signals would be ignored, and that its goal was to effectively give an illusion of privacy while still catering to their own interests.[30] On October 9, 2012, Fielding's patch was commented out, restoring the previous behavior.[31][32]

On April 3, 2015, Microsoft announced that starting with Windows 10, it would comply with the specification and no longer automatically enable Do Not Track as part of the operating system's "Express" default settings, but that the company will "provide customers with clear information on how to turn this feature on in the browser settings should they wish to do so".[33]


Very few advertising companies actually supported DNT, due to a lack of regulatory or voluntary requirements for its use,[34] and unclear standards over how websites should respond to the header. Websites that honor DNT requests include Medium and Pinterest.[35] Despite offering the option in its Chrome web browser, Google did not implement support for DNT on its websites, and directed users to its online privacy settings and opt-outs for interest-based advertising instead.[10] The Digital Advertising Alliance, Council of Better Business Bureaus and the Direct Marketing Association does not require its members to honor DNT signals.[36]

Use of ad blocking software to block web trackers and advertising has become increasingly common (with users citing both privacy concerns and performance impact as justification), while Apple and Mozilla began to add privacy enhancements (such as "tracking protection") to their browsers, that are designed to reduce undue cross-site tracking. In addition, laws such as the European Union's General Data Protection Regulation (GDPR) have imposed restrictions on how companies are to store and process personal information.[10][37]

Princeton University associate professor of computer science Jonathan Mayer, who was a member of the W3C's working group for DNT, argued that the concept is a "failed experiment".[10]

Global Privacy Control[edit]

Global Privacy Control (GPC) is a proposed HTTP header field and DOM property that can be used to inform websites of the user's wish to have their information not be sold or used by ad trackers.[38] GPC was developed in 2020 by privacy technology researchers such as Wesleyan University professor Sebastian Zimmeck and former Chief Technologist of the Federal Trade Commission Ashkan Soltani, as well as a group of privacy-focused companies including the Electronic Frontier Foundation, Automattic (owner of Tumblr and WordPress), and more.[15] The signal has been implemented by DuckDuckGo's privacy extension, The New York Times, and privacy browser Brave and is supported by Firefox creator, Mozilla as well as former California Attorney General Xavier Becerra.[39][40][41] GPC is a spiritual successor to the Do Not Track header that was created in 2009 but didn't find widespread success due to the lack of legislation that would require companies to legally respect the Do Not Track header.[42]

GPC is a valid do-not-sell-my-personal-information signal according to the California Consumer Privacy Act (CCPA), which stipulates that websites are legally required to respect a signal sent by users who want to opt-out of having their personal data sold.[43][44][45][46][47][48] In July 2021, the California Attorney General clarified through an FAQ that under law, the Global Privacy Control signal must be honored.[49][50]

On August 24, 2022, the California Attorney General announced Sephora paid a $1.2-million settlement for allegedly failing to process opt-out requests via a user-enabled global privacy control signal.[51]

See also[edit]


  1. ^ Soghoian, Christopher (January 21, 2011). "The History of the Do Not Track Header". Slight Paranoia. Retrieved February 22, 2012.
  2. ^ a b Julia Angwin (January 21, 2011). "Web Tool On Firefox To Deter Tracking". Wall Street Journal. Retrieved February 22, 2012.
  3. ^ "IE9 and Privacy: Introducing Tracking Protection". IE Blog. December 7, 2010. Archived from the original on December 25, 2010.
  4. ^ a b Nick Wingfield (April 14, 2011). "Apple Adds Do-Not-Track Tool to New Browser". Wall Street Journal. Retrieved April 14, 2011.
  5. ^ a b Opera Desktop Team (February 11, 2012). "Core update with Do Not Track, and mail and theme fixes". Opera blog. Archived from the original on March 10, 2013. Retrieved February 10, 2012.
  6. ^ a b "Longer battery life and easier website permissions". Chrome blog. November 6, 2012. Retrieved November 7, 2012.
  7. ^ "W3C Tracking Protection Working Group".
  8. ^ Schunter, Matthias (November 6, 2018). "Final version of the note". public-tracking (Mailing list).
  9. ^ "Tracking Preference Expression (DNT)".
  10. ^ a b c d "'Do Not Track' Privacy Tool Doesn't Do Anything". Gizmodo. October 15, 2018. Retrieved October 24, 2019.
  11. ^ a b "WG closed · w3c/dnt@5d85d6c". GitHub. Retrieved February 7, 2019.
  12. ^ a b Hill, Kashmir (February 6, 2019). "Apple Is Removing 'Do Not Track' From Safari". Gizmodo. Retrieved February 7, 2019.
  13. ^ a b "Apple is removing the Do Not Track toggle from Safari, but for a good reason". Macworld. February 7, 2019. Retrieved October 24, 2019.
  14. ^ "How do I turn on the Do Not Track feature? | Firefox Help". Mozilla Support. Mozilla Foundation. Retrieved March 8, 2023.
  15. ^ a b c "Announcing Global Privacy Control: Making it Easy for Consumers to Exercise Their Privacy Rights" (Press release). October 7, 2020. Retrieved March 8, 2023.
  16. ^ Goodin, Dan (October 8, 2020). "Now you can enforce your privacy rights with a single browser tick". Ars Technica. Retrieved October 8, 2020.
  17. ^ "Do Not Track- Universal Web Tracking Opt-Out". Retrieved April 11, 2011.
  18. ^ "The History of the Do Not Track Header" (PDF). Center for Democracy and Technology. October 31, 2007. Retrieved February 22, 2012.
  19. ^ Zetter, Kim (August 17, 2009). "Outspoken Privacy Advocate Joins FTC". Wired News. Retrieved November 20, 2009.
  20. ^ Corbin, Kenneth (July 28, 2010). "FTC Mulls Browser-Based Block for Online Ads". Internet News. Retrieved November 20, 2009.
  21. ^ Angwin, Julia (December 2, 2010). "FTC Backs Do-Not-Track System for Web". Wall Street Journal. Retrieved February 22, 2012.
  22. ^ Angwin, Julia (December 7, 2010). "Microsoft to Add 'Tracking Protection' to Web Browser". Wall Street Journal. Retrieved February 22, 2012.
  23. ^ Angwin, Julia (March 15, 2011). "Microsoft Adds Do-Not-Track Tool to Browser". Wall Street Journal. Retrieved February 22, 2012.
  24. ^ Abel, Jennifer (August 6, 2015). "Privacy groups offer "Do Not Track" compromise; will online advertisers and publishers accept it?". ConsumerAffairs. Retrieved August 10, 2015.
  25. ^ "Internet Explorer 10 Released for Windows 7". PC Magazine. November 13, 2012. Retrieved December 22, 2012.
  26. ^ Brendon Lynch (August 7, 2012). "Do Not Track in the Windows 8 Setup Experience". Microsoft on the issues blog. Archived from the original on August 8, 2012.
  27. ^ "Microsoft ticks off advertisers with IE10 'Do Not Track' policy". CNET. June 1, 2012. Retrieved September 8, 2012.
  28. ^ "Microsoft's "Do Not Track" Move Angers Advertising Industry". Digits. The Wall Street Journal. Retrieved September 8, 2012.
  29. ^ "Microsoft sticks to its guns, keeps Do Not Track on by default in IE10". Ars Technica. August 8, 2012. Retrieved May 14, 2013.
  30. ^ "Apache Web software overrides IE10 do-not-track setting". CNET. Retrieved September 8, 2012.
  31. ^ "Apache Won't Override Do-Not-Track Headers". MediaPost Communications. October 9, 2012. Retrieved December 22, 2012.
  32. ^ "Keep this in, but commented out: also provide a little · apache/httpd@3dd6fb6". GitHub. Retrieved July 4, 2017.
  33. ^ "Microsoft rolls back commitment to Do Not Track". Computerworld. IDG. April 3, 2015. Retrieved April 3, 2015.
  34. ^ "Here's The Gaping Flaw in Microsoft's 'Do Not Track' System For IE10". Business Insider. Retrieved September 8, 2012.
  35. ^ Bacchus, Arif (October 15, 2018). "Millions of People Use 'Do Not Track' Tool Which Does Nothing". Digital Trends. Designtechnica Corporation. Retrieved November 1, 2019.
  36. ^ "Digital Advertising Alliance Gives Guidance to Marketers for Microsoft IE10 'DO NOT TRACK' Default Setting". Retrieved October 10, 2012.
  37. ^ Fleishman, Glenn (March 17, 2019). "How the tragic death of Do Not Track ruined the web for everyone". Fast Company. Retrieved October 24, 2019.
  38. ^ "Global Privacy Control — Take Control Of Your Privacy". Retrieved July 23, 2021.
  39. ^ "'Do Not Track' Is Back, and This Time It Might Work". Wired. ISSN 1059-1028. Retrieved December 27, 2020.
  40. ^ "Now you can enforce your privacy rights with a single browser tick". Ars Technica. Retrieved January 2, 2021.
  41. ^ "Global Privacy Control emerges as latest attempt to let netizens choose whether they want to be tracked online". The Register. Retrieved January 2, 2021.
  42. ^ "Global Privacy Control Protocol Aims to Pick Up Where Do Not Track Left Off". Decipher. Retrieved December 27, 2020.
  43. ^ "Tech-publisher coalition backs new push for browser-level privacy controls". TechCrunch. Retrieved December 27, 2020.
  44. ^ Shankland, Stephen. "Privacy push could stop some annoying website pop-ups and online tracking". CNET. Retrieved December 27, 2020.
  45. ^ "Global Privacy Control initiative aims to help consumers exercise privacy rights". International Association of Privacy Professionals. Retrieved December 27, 2020.
  46. ^ "DuckDuckGo, EFF, and others just launched privacy settings for the whole internet". Fast Company. Retrieved December 27, 2020.
  47. ^ "California Consumer Privacy Act (CCPA)". State of California - Department of Justice - Office of the Attorney General. October 15, 2018. Retrieved December 27, 2020.
  48. ^ "View Document - California Code of Regulations". Retrieved July 23, 2021.
  49. ^ "CCPA update: Businesses must immediately support the Global Privacy Control (GPC) signal". Transcend. July 21, 2021. Archived from the original on September 28, 2021. Retrieved July 23, 2021.
  50. ^ "California Consumer Privacy Act (CCPA)". State of California - Department of Justice - Office of the Attorney General. October 15, 2018. Retrieved July 23, 2021.
  51. ^ "Attorney General Bonta Announces Settlement with Sephora as Part of Ongoing Enforcement of California Consumer Privacy Act". State of California - Department of Justice - Office of the Attorney General. August 24, 2022.

External links[edit]