In statements released on Wednesday US time, the two companies slammed the move by Google, with Vivaldi chief executive Jon von Tetzchner calling the new data harvesting venture "nasty".
DuckDuckGo said FLoC was bad for privacy. "Google has created a new tracking method called FLoC, put it in Chrome, and automatically turned it on for millions of users," the company said.
"FLoC is bad for privacy: It puts you in a group based on your browsing history, and any website can get that group FLoC ID to target and fingerprint you."
Everybody knows to not put all their eggs in one basket but Google seems to be putting more and more of their eggs into the tracking basket and their other services are starting to suffer because of it.— Chris Jeter (@ChrisJeter7) April 9, 2021
A blog post by EFF staff technologist Bennett Cyphers said the only way people could opt out at the moment was by disabling third-party cookies. "We’ve been told that the trial is currently deployed to 0.5% of Chrome users in some regions – for now, that means Australia, Brazil, Canada, India, Indonesia, Japan, Mexico, New Zealand, the Philippines, and the US," he wrote.
Two senior executives from Brave, senior privacy researcher Peter Snyder and chief executive Brendan Eich made their opposition known on Monday US time, saying ""Brave opposes FLoC, along with any other feature designed to share information about you and your interests without your fully informed consent".
DuckDuckGo said: "You can use the DuckDuckGo Chrome extension to block FLoC's tracking, which is an enhancement to its tracker blocking and directly in line with the extension's single purpose of protecting your privacy holistically as you use Chrome.
"DuckDuckGo Search (via our website duckduckgo.com) is now also configured to opt-out of FLoC, regardless if you use our extension or app."
FLoC groups you based on your interests & demographics, using your browsing history, to enable creepy advertising & other content targeting without third-party cookies. It continues to facilitate the manipulation, discrimination, and filter bubbles synonymous with such targeting.— DuckDuckGo (@DuckDuckGo) April 9, 2021
The smaller search engine company said Google had not been very clear about how one could avoid being tracked by FLoC, but suggested the following to avoid becoming a target:
- "Stay logged out of your Google account;
- "Don't sync your history data with Chrome, or create a sync passphrase;
- "In Google Activity Controls, disable 'Web & App Activity' or 'Include Chrome history and activity from sites, apps, and devices that use Google services';
- "In Google Ad Settings disable 'Ad Personalisation' or 'Also use your activity & information from Google services to personalise ads on websites and apps that partner with Google to show ads'."
Von Tetzchner said while Vivaldi also used the engine from Chromium - the open-source browser made by Google - to render pages correctly, that was where the similarity with Chrome ended.
"At Vivaldi, we stand up for the privacy rights of our users. We do not approve tracking and profiling, in any disguise. We certainly would not allow our products to build up local tracking profiles," he said.
Von Tetzchner said Vivaldi would not support the FLoC API. "We will not support the FLoC API and plan to disable it, no matter how it is implemented. It does not protect privacy and it certainly is not beneficial to users, to unwittingly give away their privacy for the financial gain of Google."
He said the reason why FLoC had been devised was because third-party cookies were dying. "Traditionally, many websites relied legitimately on third-party cookies to maintain logins. Blocking third-party cookies would break these logins. But because these were abused for tracking, some browsers started blocking third-party cookies anyway," he explained.
"Websites have steadily moved towards alternative solutions for logins that do not rely on third-party cookies, and very soon, third-party cookies could be disabled by default in all browsers.
"This presents a challenge for ‘tracking’ companies such as Google who want to remain dominant, and so they look for alternatives. FLoC is one of them.