District Judge Lucy Koh in the state of California ruled that Google "did not notify users that Google engages in the alleged data collection while the user is in private browsing mode", reports Bloomberg.
A Google spokesperson told The Verge on Saturday that the company disputes the lawsuit's claims.
"We will defend ourselves vigorously against them," the spokesperson was quoted as saying in the report.
Google Chrome's 'Incognito' mode gives users choice to browse the internet without their activities being saved to either browser or devices.
"As we clearly state each time you open a new incognito tab, websites might be able to collect information