W3C Workshop on Web Tracking and User Privacy

One topic that is getting a lot of press lately is privacy on the Internet, especially web tracking [Notes].

The W3C held a “Workshop on Web Tracking and User Privacy” on 28/29 April 2011, for which an agenda with links to presentations workshop papers and a final report are available.

This is a difficult topic since there is a need for a balance between what appears to be a legitimate need to enable advertising-based business models to support “free” content and the ability of users to protect their privacy, not losing control over their own personal data.  

Discussion at the workshop reflected the privacy needs of individuals on the web as well as support for business models driven by advertising. Technical proposals such as an HTTP do not track header and use of tracking protection lists were considered.

Ed Felton of the FTC noted five desired properties of a “Do Not Track” mechanism in his slides:

  1. Is it universal? Will it cover all trackers? 
  2. Is it usable?  Easy to find, understand and use?
  3. Is it permanent? Does opt-out get lost? 
  4. Is it effective and enforceable? Does it cover all tracking technologies? 
  5. Does it cover collection in general and not just some uses like ads? 

A significant issue noted at the workshop is that “user expectations may  not match what is implemented”. One example is that the discussion is not about “opting out of ads” but out of “tracking”, so even with opt-out, ads might still appear.  More complicated for users is that nuances might be possible such as allowing 1st party tracking but not third party tracking – yet what does this mean at the edge cases? Is a subsidiary a third party? What about outsourced work? This could be confusing for users and lead to results that are not what they expect or want. As mentioned at the workshop, the details will matter here.

Craig Wills of the Computer Science Department, Worcester Polytechnic Institute noted that first parties have a responsibility for not “leaking” privacy information to third parties by not being careful in their implementations. This is detailed in his paper.

Helen Nissbaum made an important point during the discussion. Consent is not always needed, but only when user expectations are not met (or there is a risk of not meeting user expectations, I assume). Consent is not needed every step of the way. This relates to the theme of avoiding unnecessary user interaction, avoiding meaningless dialogs and increasing usability.

Questions to ask before tracking include:

  1. Is  it necessary to collect the data
  2. Can the goal be accomplished another way, with less data

Regulations and laws should not be overly prescriptive with respect to technology details, otherwise as the technology changes they lose effect. Instead they should focus on the policy and goals. This is similar to mandating fuel efficiency in cars rather than the way it is achieved.

Apparently enabling some tracking but not all tracking, for a variety of parties, is difficult.

Workshop participants recognized the complexity and difficulties of the topic but also the need for steps to be taken in the near term. During the workshop goals were mentioned that included providing  transaction transparency, relevant information, and  meaningful user choices. It is clear that some changes may be required.
Workshop participants noted that there is much research into the economics of “do not track”.

John Morris of CDT enumerated in his slides the typical objections raised with respect to implementing mechanisms to increase user privacy and indicated how they might be addressed, for example relying on  non-technical mechanisms such as reputation, law or regulation rather than technology for enforcement. 

Given the various stakeholders and concerns, the principle of doing what is “reasonable” seems to apply here, just as in other aspects of law. 

Thus it is not surprising that there was general acceptance by workshop participants of adopting a middle-ground approach – specifically there was no objection to the proposal from CDT that includes the following definition:
“Tracking is the collection and correlation of data about the web-based activities of a particular user, computer, or device across non-commonly branded websites, for any purpose other than specifically excepted third-party ad reporting practices, narrowly scoped fraud prevention, or compliance with law enforcement requests.”

As noted in the W3C workshop report, possible next steps include the W3C chartering a general Interest Group to consider ongoing Web privacy issues and a W3C Working Group to standardize technologies and explore policy definitions of tracking.


[1] Retargeting Ads Follow Surfers to Other Sites, August 29, 2010, New York Times

[2] How to Fix (or Kill) Web Data About You, April 13, 2011,  New York Times

[3] Tracking File Found in iPhones, April 20, 2011, New York Times

[4] Apple, Google Collect User Data, April 22, 2011, Wall Street Journal

[5] Avoiding Mobile Trackers, April 22, 2011, Wall Street Journal

[6] Facebook hit by privacy complaints, June 9, 2011 Financial Times

(edit – added paragraphs at end re CDT proposal)