Google has announced plans to stop using tracking cookies in its Chrome browser by 2022 and replace them with a group profiling system. According to the company, this should represent “a course in the direction of a more privacy-friendly web”.
The change is substantial. Chrome dominates around two thirds of the web browser market. Third-party tracking cookies are now underpinning a large part of the advertising target industry. While Mozilla’s Firefox and Apple’s Safari have already stopped supporting third-party cookies, Google is the first to support replacement advertising.
Instead of tracking and targeting you individually, Google’s alternative instead groups you into a crowd with similar general interests. Google argues that this gives users more privacy. Oddly enough, this comes with assurances to advertisers that the new technique will be at least 95% as effective as individual targeting.
However, amid the glitz of Google’s press releases, the shift from tracking to profiling raises a number of new privacy and discrimination concerns. Chrome’s new system is supposedly a step towards improving individual privacy and should ultimately benefit Google. This gives the company another advantage over its beleaguered AdTech competitors.
Google Chrome is the world’s dominant web browser, just like Google Search is the world’s leading search engine. Flystock / Shutterstock
Cookies for cohorts
The traditional web tracking and targeting method uses so-called cookies: small files that are stored by web browsers such as Chrome. Its original purpose was to keep information – such as the items you added to online shopping carts – between browsing sessions. This was seen as useful to consumers.
Nowadays cookies are mainly used for advertising purposes. Third party vendors use cookies in Chrome to track you across the web. Sufficient data on your surfing habits is collected in order to address you with highly specific ads.
Given how invasive this tracking has become, EU data protection laws classify cookies as “online identifiers”. This is subject to regulations that require websites to obtain your consent before they can send cookies to your browser.
Google’s new Chrome system will give up on this. Instead, the browser uses your most recent browsing history to generate your “cohort identity”. This is currently achieved through the use of a “simhash” which, in simple terms, generates “magic numbers” to represent your interests before being grouped with those who have similar numbers.
Tucked away in a cohort of a few thousand people, you have ads aimed at your cohort rather than you as an individual. This is presented as an incentive for privacy as it moves away from the individualized tracking and targeting that has made third-party cookies particularly invasive.
On the way to the Facebook model
Conceptually, the system proposed by Google is not new – it is a form of profiling that enables an advertising model that Facebook has been using for some time. Targeting a person’s cohort identity is like creating a “lookalike audience” based on a person. This is a service that Facebook is currently offering to advertisers.
We should expect profiling to also create a number of cohorts of different names that advertisers can use to create custom audiences with mixed interests – something Facebook also offers.
Facebook has served advertisers with profiling-based ads for many years. PixieMe / Shutterstock
This is where profiling becomes problematic. In 2016, it was revealed that Facebook allowed advertisers to exclude users based on their race. Even after Facebook made changes to its target groups, advertisers were able to discriminate on the basis of sensitive interests, which were predominantly represented by minorities.
Profiling includes machine learning algorithms and AI technologies that have been repeatedly shown to reinforce the real trend. Hence, Google’s decision to lay off key members of the AI ethics team while Chrome launches an advertising model for profiling seems particularly alarming.
Aside from the known harms and risks of profiling, it’s unclear how Google’s new model improves individual privacy. In order for the system to work, Chrome has to voluntarily provide your cohort identity for every website you visit, while a third-party cookie will not show this volume of data for all websites.
The smaller the cohorts get, the easier it is for you to spot them. And you’d expect Google to give preference to smaller cohorts as larger cohorts naturally decrease the accuracy of targeted advertising. Overall, the change will bring a number of new risks to privacy and discrimination. Otherwise, why might Google choose to scrap third-party cookies on Chrome?
Google’s mixed motivations
One reason is regulation. The EU’s new ePrivacy Directive could well result in the traditional use of tracking cookies being abolished in the EU anyway, which has far-reaching consequences for other jurisdictions. So Google can just jump before it’s pushed.
By limiting how third page Advertising services can use Chrome. Google may also benefit from suppressing competition. An advocacy group for online advertisers has already asked the UK competition watchdog to consider the Chrome change as part of its existing investigation into Google’s advertising practices. Google itself retains numerous tracking options after the change, especially if Chrome users are logged into their Google accounts.
Google is the biggest beneficiary of Chrome’s move from cookies to cohorts. Google’s new system only slightly restricts the reach of traditional targeted advertising and expands its repertoire to include Facebook’s profile-based advertising method.
By now, end users like you and I will hardly notice a difference. We will continue to be monitored and targeted through our online activities – only now as part of a group and not as an individual.
This article by Eerke Boiten, Professor of Cybersecurity, Faculty of Computer Science and Computer Science, De Montfort University, is republished by The Conversation under a Creative Commons license. Read the original article.
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