Last month, Google unveiled its Federated Learning of Cohorts (FLoC) technology, which allows the web giant to deliver personalized ads and track users. This new tech will supposedly replace "cookies" which have raised the hackles of privacy defenders.

According to Google, FLoC hides individuals 'in the crowd' and uses on-device processing to keep a person’s web history private on the browser.

Google plans to begin testing the FLoC approach with advertisers later this year with its Chrome browser.

Safari and Firefox browsers have already done away with third-party cookies, but they are still used at the world's most popular browser - Chrome.

Some have worries about Google using a secret formula to lump internet users into groups and give them "cohort" badges of sorts that will be used to target marketing messages without knowing exactly who they are, thus makes a lot of privacy problems worse.

Some marketers and advertisers for an Open Web business coalition is campaigning against Google's cohort move, questioning its effectiveness and arguing it will force more advertisers into its "walled garden."