Facebook CEO Mark Zuckerberg. TechCrunch/Flickr (CC) Facebook has been accused of violating the privacy of its users by collecting their facial data, according to a class-action lawsuit filed last week.

This data-collection program led to its well-known automatic face-tagging service. But it also helped Facebook create “the largest privately held stash of biometric face-recognition data in the world,” the Courthouse News Service reports.

The lawsuit alleges that this facial-recognition program violates the privacy of its users, citing an Illinois law called the Illinois Biometrics Information Privacy Acts, which requires companies to get written content from a user if it is collecting biometric data.

Further, according to the statute, the company must state the purpose and length of its data-collection program.

The lead plaintiff, Carlo Licata, claims that Facebook's biometric program shows “brazen disregard for its users’ privacy writes.” He added that the way changing user settings will not change what biometric data the company collects, the Chicago Tribune reports.

Facebook has been under fire over this feature for years. It first began offering the tagging service through a technology from Israeli company Face.com, which Facebook acquired in 2012.

A Senate hearing was held in 2012 to discuss this specific program. At the hearing, Facebook’s Robert Sherman rebutted that the “tag suggestions” program is “merely a ‘convenience feature’ and that users’ data is secure,” according to the report.

Courthouse News Service writes:

The company's faceprint database works only with its own software, and "alone, the templates are useless bits of data," Sherman said. He said that users can opt out of the feature and their data will be deleted.

In 2012, Facebook stopped offering the facial-recognition feature in Europe because of privacy concerns, according to The New York Times.

Business Insider reached out to Facebook for comment. A spokesperson wrote, "This lawsuit is without merit and we will defend ourselves vigorously."

Licata's intention is to get a court injunction that requires Facebook to put a halt to the program.