EU privacy group Noyb acclaims Firefox's tracking of users without their consent with its “Privacy-Preserving Attribution” (PPA). Noyb argues this is misdirection. If EU regulators agree, Mozilla could face orders to change or a penalty of up to four percent of global revenue.

Noyb said that contrary to its reassuring name, this technology allows Firefox to track user behaviour on websites,” noyb wrote in a press release.

“In essence, the browser is now controlling the tracking rather than individual websites. While this might be an improvement compared to even more invasive cookie tracking, the company never asked its users if they wanted to enable it. Instead, Mozilla decided to turn it on by default once people installed a recent software update. This is particularly worrying because Mozilla generally has a reputation for being a privacy-friendly alternative when most other browsers are based on Google’s Chromium.”

Noyb argues that Mozilla’s move “doesn’t replace cookies either.” Firefox lacks the market share to shift industry practices, creating another way for websites to target ads.

The Noyb-backed complaint, filed with the Austrian data protection authority, accuses Mozilla of failing to inform users about data processing and using an opt-out mechanism. The group wants the regulator to order the deletion of all collected data.

Mozilla’s director of policy and corporate communications, Christopher Hilton, stated that only a “limited test” of a PPA prototype was conducted on its websites. He acknowledged poor communication but emphasized that no user data was collected or shared.

He said Mozilla is committed to engaging with stakeholders as it develops the technology further.