For the second time this month, Facebook was hit with a privacy lawsuit in Illinois over its face-recognition technology. Users of mobile devices are silhouetted in front of a screen on which the Facebook logo is projected, in this picture illustration taken in Zenica, Federation of Bosnia and Herzegovina, Oct. 29, 2014. Reuters

For the second time this month, Facebook Inc. was hit with a class-action lawsuit claiming its face-recognition technology violates an Illinois state law that prohibits companies from collecting certain types of biometric data without first obtaining informed, written consent.

The lawsuit, filed Tuesday in U.S. District Court in northern Illinois, says the technology raises “serious privacy concerns” and has allowed the social media giant to amass a large-scale database of sensitive and personal data with a “large potential of misuse.” Adam Pezen, the single named plaintiff in the suit, is a resident of Chicago and has been a Facebook member since 2005, according to the legal complaint.

The complaint centers on Facebook’s photo-tagging feature, which scans faces in photos uploaded to Facebook and then suggests tags based on the user’s friends. Lawyers for Pezen say the technology has allowed Facebook to collect and store millions of “face templates,” and the company has not explained to users what it is doing with that information or advised them it is collecting it.

Facebook has even collected such data on nonusers, the lawsuit claims, by scanning photos and creating “shadow profiles” of people whose photos are uploaded to the site but do not have Facebook accounts.

From the complaint:

“Face templates are digital maps of facial points which are sometimes referred to in the biometric industry as ‘face prints,’ which is a digital biometric template specific to facial recognition technology. Facebook extracts geometric data from photos uploaded by Facebook members to create a highly detailed geometric map (i.e., the ‘face template’) of the user’s face.”

A Facebook spokesperson did not immediately respond to a request for comment.

The lawsuit is at least the second this month accusing Facebook of violating Illinois’ 2008 Biometric Information Privacy Act, which among other things makes it illegal to collect biometric data without written consent from individuals whose data is collected. The earlier suit was filed April 1 in Cook County Court by Edelson PC, a Chicago law firm noted for its privacy lawsuits against Silicon Valley tech giants like Amazon.com Inc., Google Inc. and Apple Inc. Jay Edelson, the firm’s founder, was the subject of a recent New York Times profile in which he was referred to as “tech’s least friended man.”

The most recent lawsuit was filed in federal court by a different firm, Lasky & Rifkind. Lawyers are asking for statutory damages of $5,000 per violation for what they call the “intentional and reckless” violation of state law.

Read the full legal complaint here.

Facebook Face Recognition Lawsuit

Christopher Zara is a senior writer who covers media and culture. News tips? Email me here. Follow me on Twitter @christopherzara.