An Illinois man has sued Snapchat for alleged violations of a state law that requires users to expressly consent to instances in which their biometric information is used.

This is the second time a plaintiff has brought such a case under the Illinois Biometric Information Privacy Act (BIPA). Last year, a Chicago man sued Facebook on similar claims.

The proposed class-action lawsuit, known as Jose Martinez v. Snapchat, was originally filed in May 2016 in a Los Angeles County court but was transferred to federal court on Thursday at Snapchat’s behest.

Back in September 2015, the Los Angeles-based startup acquired a facial recognition firm called Looksery. Snapchat then incorporated features from Looksery's selfie app (also called Looksery) into a new app dubbed “Lenses.” These features, which allow the app to draw animated additions to a person's face, quickly became one of Snapchat’s most popular.

However, in order to make those animations work, the app has to scan a person’s face and store its biometric identifiers. And that, according to the lawsuit, is exactly the problem.

As Martinez’s lawyers argue: "Snapchat never informed Illinois users, such as Plaintiffs, of the specific purpose and length of term for which their biometric identifiers or information would be collected, stored, and used, nor did Snapchat obtain a written consent or release from any of these users."

Further, Snapchat lacks a clear, cohesive policy for destroying such acquired biometric data.

However, one legal expert told Ars that this case may not be quite the same as the other facial recognition case filed against Facebook.

“In this particular case, it's not clear that Snapchat even used face recognition technology in a way that would implicate BIPA,” Yana Welinder, a lawyer and legal fellow with Stanford University, e-mailed. “It's possible that they are simply using face detection technology. If so, that would be similar to what many digital cameras do to identify a face in an image to focus the lens on the face.”

Snapchat did not immediately respond to Ars’ request for comment.

UPDATE 2:00pm ET: Snapchat spokesman Noah Edwardsen e-mailed Ars with this statement: "Contrary to the claims of this frivolous lawsuit, we are very careful not to collect, store or obtain any biometric information or identifiers about our community."