On Thursday, a judge in Northern California District Court rejected a motion by Facebook for the dismissal of a lawsuit which accuses the social network of violation of user privacy via its photo-tagging feature.

By turning down Facebook's motion to have the lawsuit dismissed, US District Judge James Donato has given permission for the lawsuit to proceed. The lawsuit chiefly revolves around Facebook's use of facial recognition technology, without users' consent, for its photo-tagging feature.

According to the lawsuit, which is in the form of a class-action complaint by three Facebook users from Illinois, Facebook's violation of user privacy is rooted in the fact that the company scans the faces of its users without explicit permission, and enables others to "tag" them in photos.

The plaintiffs have sued Facebook under an Illinois state law, the Biometric Information Privacy Act (BIPA), which regulates the manner in which 'biometric identifiers' -- including iris scans and 'face geometry' -- are used by companies. A violation of the law involves penalties of $1,000 or $5,000.

In his ruling against Facebook, Judge Donato agreed with the argument in the lawsuit that Facebook's scanning and tagging feature can be considered as the use of 'biometric identifier' covered by the Illinois BIPA statute.