A US federal judge ruled that Facebook would need to face a suit by a group of Illinois-based users who claim the platform violated their biometric privacy. The users say the company had used its facial recognition tool on their photos without their consent.

The lawsuit filed by Illinois residents Nimesh Patel, Adam Pezen, and Carlo Licata was "sufficiently cohesive to allow for a fair and efficient resolution on a class basis," Judge James Donato ruled on Monday.

The approval is an important step on the road to trial or settlement for US class action lawsuits.

Read more: Facebook - dismantling an internet superstar

Facebook introduced the tool in 2010 to help users tag their friends in photos. The "Tag Suggestions" software would analyze faces and suggest users' names. EU regulators forced Facebook to suspend this technology in Europe in 2012 over privacy fears. The social media platform insists it is transparent about the tool's use and that it allows users to turn it off.

Commenting on the latest ruling, Facebook said it was still reviewing the decision.

"We continue to believe the case has no merit and will defend ourselves vigorously," a Facebook spokeswoman said.

The court's decision comes as the company struggles with the Cambridge Analytica controversy that has seen the data of some 87 million users being mishandled in a wide-reaching privacy scandal.

Also on Monday, Facebook admitted to also collecting online information from people who are not their users.

"When you visit a site or app that uses our services, we receive information even if you're logged out or don't have a Facebook account," product management director David Baser said in an online post. According to the Facebook representative, many websites and apps use Facebook's services to target their content and ads. Baser added Google and Twitter were doing the same.

dj/rc (AFP, Reuters)