Facebook was unsuccessful in shoving a dagger in a lawsuit that alleges the company violated user privacy when it introduced Tag Suggestion system, which auto-tags users on photos. The case will move forward, now that a federal judge in San Francisco has thrown out Facebook's motion to dismiss it.

Facebook had asserted that the litigants failed to present a valid claim under the Biometric Information Privacy Act (BIPA) established by the state of Illinois, where the lawsuit was raised before plaintiffs agreed to transfer the case to California.

California is Facebook's venue of choice because a provision in the company's user agreement asserts that it is protected by the said state's choice-of-law clause, which specifically bars users from using Illinois statutes to sue.

U.S. District Judge James Donato sided with the plaintiffs on both points. Illinois law applies, despite the case being transferred to California, and that the filed claim under Illinois' BIPA is a legitimate one.

Facebook's motion to dismiss the case on the grounds that the BIPA definitions for "biometric information" and "biometric identifier" excludes pictures and data extracted from photos.

"The Court accepts as true plaintiffs' allegations that Facebook's face recognition technology involves a scan of face geometry that was done without plaintiffs' consent," the judge wrote. "Consequently, they have stated a plausible claim for relief under BIPA."

The Tag Suggestions was trumpeted by Facebook as a tool to help users tag one another in pictures on the company's social network. The system learns to recognize an individual's face and stores what it has learned, so that it can spot a person next time he or she is in an uploaded photo.

With 1.65 billion people actively use Facebook, the federal judge said that the company has "secretly amassed the world's largest privately held database of consumer biometric data." The database would have names, life stories, personal contacts and the ability to match faces to that information and more.