Google Chrome application icon on mobile phone showing DuckDuckGo Chrome Extension blocks ad targeting

DuckDuckGo Escalates Showdown With Google; Chrome Extension Now Blocks Google Topics and FLEDGE Ad Targeting System

DuckDuckGo has been engaged in a back-and-forth battle with Google over user privacy as of late, and the company has fired another shot by enabling its Chrome extension to block Google’s new “privacy focused” ad targeting system.

Google has been wheeling out its new “Privacy Sandbox” ad targeting approach in stages, focusing on making changes to its Chrome browser as the first steps. The system attempts to make personalized advertising more private by placing users in client-side interest groups, but it has been criticized by a number of privacy advocates.

DuckDuckGo Chrome extension allows users to duck out of the privacy sandbox

A blog post from DuckDuckGo announced that two central components of Google’s Privacy Sandbox, FLEDGE and Google Topics, could now be blocked either individually or together in its recently-updated Chrome extension. Together, FLEDGE and Topics are meant to replace the standard tracking cookie used for ad targeting (which Google intends to put an end to in Chrome by the end of 2022). The system is supposed to enhance privacy by putting users in “interest buckets” instead of building individual profiles on them, with the processing of those buckets handled browser-side so that third parties have very limited access to it.

DuckDuckGo’s concerns about the privacy sandbox echo those already raised by both digital privacy groups and national regulators around the world. Regulators have tended to be more concerned with the antitrust end of the proposal, speculating that Google will force the digital advertising market to route itself through this technology. Privacy advocates point out that Google will also still have access to information about potentially sensitive demographic categories, and that it is not impossible for third party advertisers to use this system to identify and track individuals. DuckDuckGo’s Chrome extension thus already has an interested market in spite of Google’s new systems not yet being finalized.

The criticism is not particularly well-timed for the DuckDuckGo Chrome extension given the recent revelation that its web browser, which is touted as blocking all third-party user tracking, has been quietly allowing Microsoft-owned services (such as Bing and LinkedIn) to track and profile users. DuckDuckGo did not disclose this to the public, and it only came to light when a security researcher tracked traffic from the browser and found it feeding information to Microsoft ad targeting services. This forced the CEO of DuckDuckGo to disclose that its contractual search partnership with Microsoft requires them to allow this sort of user tracking.

FLoC to FLEDGE: Google’s change of ad targeting plans

When Google first announced the Privacy Sandbox concept about two years ago, the original plan was to use a system called “Federated Learning of Cohorts” (FLoC) to replace tracking cookies. The FLoC plan was scrapped in early 2022 due to criticism of its use of “cohorts” of users with similar interests as the mechanism used to deliver ads. Topics was designed to replace the cohort system with about 300 standard categories; the user will be assigned to the top three categories they are interested in based on their browsing activity over the prior three weeks, with the categories rotating at least once a month. Google has promised that Chrome users will be able to see the categories they are currently assigned to and to temporarily disable or entirely remove Topics categories they do not want to be associated with. Depending on the level of privacy controls it settles on, this could ultimately make the DuckDuckGo Chrome extension redundant.

Chrome is the only web browser that Google can force implementation of this concept into, but it appears to be hoping that other browsers will buy in to the system due to its heavyweight digital advertising program. This is the part that has raised the antennae of national antitrust regulators, who fear that Google’s dominance of the digital marketing space could essentially force everyone to use whatever ad targeting system it settles on.

Google’s Topics has alarmed privacy advocates as it does not preclude the possibility of third parties using browser fingerprinting techniques to track individuals, and could even inadvertently assist them in the process. Google has proposed to counter this with something called the “Privacy Budget,” a system that would allot websites only a certain amount of access to user information before they are cut off. Some research indicates that the system may leak information, the tracking mechanism itself could be used by wily websites as an identifier, and it could potentially break the function of websites that exceed the information limit.

The DuckDuckGo Chrome extension is available via the Google Play Store, and does not appear to allow ad targeting by Microsoft products in the way that the company’s “Privacy Browser” does. Google’s schedule for the Privacy Sandbox project has Topics and FLEDGE fully implemented in Chrome by the end of 2022, but the privacy budget is still listed as being in the “early stages” and will not be ready prior to 2024.