Google kills FLoC & will stick with cookies because of privacy complaints

Google has been planning for two years to replace cookies with other techniques used for targeted advertising to users, using a system called FLoC. On Tuesday, Google gave in to complaints about the proposed system, and is instead planning a different approach.

FLoC, a "Federated Learning of Cohorts," would replace cookies by using an in-browser algorithm, which would analyze the user's browsing history to determine the user's "interest cohort." The user would be designated a cohort number that could contain thousands of people, with advertisers able to use those same cohort numbers to target by interest.

The idea was that the system would provide a level of privacy to users, as it was calculated on the user's device, with users becoming anonymous in a sea of others within their cohort. As user browsing habits change, the algorithm would recalculate and determine new cohorts for the user, which in turn would change online advertising.

Despite the privacy aim, Google said FLoC probably doesn't enough to protect a user's identity, reports the Financial Times. It was also thought to be difficult for users to understand the system, and for them to manage how their data is being used.

The decision to pull FLoC followed after receiving feedback from publishers and marketers, project production manager Vinay Goel said.

The criticism from rival browsers including Mozilla pointed out privacy issues, such as how a cohort of a few thousand users could easily be used to track down specific users. Using browser fingerprinting, cohort users could be narrowed down to a few who could be a potential target individual.

There were also concerns that the system would be a "black box" to competitors, and would grant Google with too much control over audiences and data provided to advertisers.

Instead of FLoC, Goel said Google would be replacing it with another system called "Topics." While users would still be grouped together, the categories would be much simpler than within a cohort, such as a general "Sport" category for someone who reads about baseball.

Making the groups more general will also reduce the possibility of a user being identified within the group.

Goel said Google has yet to finalize the groupings within Topics, but would be entering discussions with publishers on the matter.

Google's FLoC decision follows after publishers and advertising groups asked EU competition chief Margrethe Vestager to intervene with the search giant's plan to block third-party cookies in Chrome in 2023.