Google has scrapped FLoC, its controversial cookie replacement. Now it’s back with Topics—but rivals and privacy experts are still nervous.
GOOGLE’S PLAN TO remove third-party cookies from Chrome hasn’t gone smoothly. Back in January 2020 the company announced it would overhaul Chrome by removing cookies that follow people around the web within two years. Well, now it’s January 2022 and Google is back with another plan. This week the company announced it was scrapping Federated Learning of Cohorts (FLoC), a key part of its plan, and replacing it with a new system called Topics.
Topics is just one element of Google’s wider Privacy Sandbox plan to bring about the end of third-party cookies in Chrome. On the face of it, it’s a move to improve user privacy. But many privacy experts have argued that it’s impact will be limited. And even the ad tech industry isn’t happy, with rivals arguing that Google is attempting to reshape online advertising in its image. In the third quarter of 2021 alone, the search giant made $53 billion from advertising—but the online world in which Google operates is changing.
When it comes to limiting third-party cookies, Google is way behind its rivals. Safari, Firefox, and Brave have all restricted them for years. Apple’s Safari started doing so back in 2017. But what Google does will have by far the biggest impact. Chrome hogs 63 percent of the global browser market—meaning Google is likely to set a standard that others might be forced to follow. After failing with FLoC, the company is now presenting Topics as a different plan for the future of online advertising. Onlookers aren’t so sure.
Topics works by analyzing your browsing history to work out the things you’re interested in. If you like cars, for example, Topics will show you adverts for cars on the websites that you visit. To work out that you like cars, each website that uses Google’s Topics API will be assigned an overall category. A website about tattooing, for instance, may fall into the body art category; a city newspaper would likely be assigned to the local news category.
As you move around the web, Chrome will record the categories you visit the most. Then, each week, your five most popular categories will be gathered up—Google says this process is done on your device and not on its servers—and a sixth random topic will be added to add some noise in the system. These six categories are then shared with the websites you visit and are used to target the ads you see. The data is deleted after three weeks.
“Topics was informed by our learning and widespread community feedback from our earlier FLoC trials,” Google product director Vinay Goel said in a blog post. That earlier system used browsing history to group people with thousands of others with similar interests. If Google’s algorithms determined you were interested in dogs, you’d be put in the same category as others who like dogs. The plan was ditched after a number of major websites and rival browsers said they wouldn’t use the system. Regulators in the EU and the UK’s Competition and Markets Authority (CMA) also opened investigations into Google’s proposals. Privacy advocates warned that it was bad for privacy, and the advertising industry wasn’t too impressed either. So how about Topics?
“There are a couple of improvements in Topics,” says Hamed Haddadi, chief scientist at Brave, a privacy-focused browser and search engine. He says that under FLoC, people could have been grouped into more than 30,000 different categories, which would allow advertisers to gain specific knowledge of their interests. This information could then be combined with other data to build up an incredibly detailed picture of each and every one of us.ADVERTISEMENT
This is less likely in Topics, as there are around 350 interest categories that can be assigned to people. Although this number is likely to increase—Google’s technical description says its eventual goal will be to source these topics from a third party, and there could be a “few thousand topics.” Haddadi also says adding a sixth random topic into people’s interests makes the system a little more privacy-conscious.
Another potential difference between FLoC and Topics is that Google claims the latter will attempt to avoid assigning “sensitive categories” to people—such as allowing individuals to be shown ads based on their race or gender. FLoC was criticized for potentially being able to generate or infer sensitive attributes through people’s behavior and interests. Google says people will be given more control over the interest areas that are assigned to them and can change settings, block topics, and opt out in Chrome. But, realistically, it’s unlikely many people will change Chrome’s settings in this way.
What’s more, the risk of websites working out someone’s sensitive personal traits isn’t completely eradicated by Topics. “It is still possible that websites calling the API may combine or correlate topics with other signals to infer sensitive information, outside of intended use,” Google’s description of Topics says. Over time it would be possible for a site to “develop a list of topics that are relevant to that user,” and this may reveal sensitive information. There are other privacy and security issues Google says it needs to fix. Google plans to test Topics in Chrome in the coming months, and the system could change based on feedback.
Then there’s the competition issue. The smaller number of interests assigned to people could potentially hand yet more power to Google in an online advertising industry it already dominates. Paul Bannister, cofounder of the ad management firm CafeMedia, says that Topics seems to be a step forward for people’s privacy, but a potential step back for advertising firms. The 350 current interests included in Topics are broad, Bannister says, and this means it’s less likely to be useful for advertisers who are trying to target individuals with products that they’re more likely to buy. “Those topics are fixed, so it’s harder to find unique segments that are really interesting to your marketing campaign,” he says.
“As it stands, Topics seems to be only a solution for the Chrome browser. It is neither cross-browser nor cross-platform,” says Phil Duffield, UK vice president at the Trade Desk, a tech and software company. The company built its own cookie-replacement rival that is based on identifiers linked to the email address people use to sign in to websites. “As with any complex technical challenge, there is no silver bullet, but we do believe in the importance of future solutions being interoperable and easily used by all players across the industry,” Duffield says.
Haddadi believes that Topics, in its current form, would improve privacy in Chrome, but that it still falls short of the standard set by almost all other browsers. “It’s just raising the bar for Chrome while a lot of other browsers, including Safari, Firefox, Brave, and Tor, already have extensive third-party blocking mechanisms.”
Ultimately, Topics may help Google stay at the top of the advertising industry for decades to come. Regulators could force Google to change its approach—the CMA’s investigation into Google’s Privacy Sandbox is still ongoing, and the regulator has already told the firm to make some changes. While Apple’s advertising business is rapidly growing, Google will still be Google. The company owns the world’s largest browser and search engine, and a huge advertising network. Topics might differ from FLoC, but it’s purpose remains the same: to maintain Google’s control over the ads we see.
Article originally appeared on Wired.