A judge in California ruled Friday that Google has to face a class action lawsuit that claims the search giant secretly collects data from users even when they’re using its private “Incognito” mode, Bloomberg reported.

Three users filed a complaint last June alleging Google has a “pervasive data tracking business,” and its tracking persists even if users take steps to protect their private information, such as using incognito mode in Chrome, or private browsing in Safari and other browsers.

The lawsuit seeks at least $5 billion.

Google had sought to have the case thrown out, but US District Judge Lucy Koh wrote in her ruling that the company “did not notify users that Google engages in the alleged data collection while the user is in private browsing mode.”

The company said in a court filing that it makes clear to users “that ‘Incognito’ does not mean ‘invisible,’ and that the user’s activity during that session may be visible to websites they visit, and any third-party analytics or ads services the visited websites use.”

Google spokesperson José Castañeda said in an email to The Verge on Saturday that the company disputes the lawsuit’s claims “and we will defend ourselves vigorously against them.”

He added that Chrome’s Incognito mode gives users the choice to browse the internet without activity being saved to their browser or devices.

“As we clearly state each time you open a new incognito tab, websites might be able to collect information about your browsing activity during your session.”

Google said earlier this year it is phasing out third-party tracking cookies, and says it doesn’t plan to replace the cookies with something that may be as invasive even though it will affect the company’s advertising business.