W3C is pleased to receive Web Tracking Protection, part of a Member Submission Request from Microsoft Corporation.
The Submission proposes to address information gathering by third parties on the Web through two different mechanisms: A filter that blocks download of third-party content (as is done, for example, through scripts and iframes in HTML), and a global "Do Not Track User Preference".
The proposed filter concerns the download of any third-party resource, where a third-party resource is defined as one whose URI includes a domain name "that differs from that of the top-level containing document." The Submission defines a simple list format to exchange filter lists of third-party URI patterns. These patterns can match both the domain part and the path component of a URI. The list permits the expression of allow and deny rules.
The "Do Not Track User Preference" is defined
to apply to all documents. This preference is expressed in an HTTP header and in
a document.navigator.doNotTrack DOM property. Web application behavior for this preference is
defined as follows:
Websites that track users across multiple first-party websites must check for the presence of the Do Not Track User Preference. If a website detects that this preference is enabled, it must disable any tracking code or collection of data that can be used for tracking purposes, regardless of the level of identification of the user.
This proposal puts additional weight behind the possibility to expose a Do Not Track User Preference to the client-side part of Web applications by augmenting the broadly discussed idea of a "do not track" HTTP header with a DOM property.
This Submission comes at a time of significant public discussion of Web tracking techniques and possible countermeasures. As a result of its strategic planning exercise for 2011, W3C had already decided to strengthen its focus on privacy. This Submission is therefore both timely and well-aligned with the consortium's objectives and priorities. The W3C Staff is preparing a Workshop at Princeton University on 28-29 April 2011 to assess the degree of support for W3C to take up Recommendation-track work in this area. An official announcement is expected in early March 2011.
We expect to engage a broad set of stakeholders, including implementers from the mobile and desktop space, large and small content delivery providers, advertisement networks, search engines, policy and privacy experts, experts in consumer protection, and developers and operators of Services on the Web that make use of consumer tracking.
At this stage, we invite expression of interest and support, community comment, discussion on this Submission and input concerning the workshop to the public-privacy@w3.org mailing list (public archive; subscribe to this list).