The US Civil Liberties Union (ACLU) took the controversial facial scan company Clearview to court on Thursday for violating the privacy of citizens. Clearview made headlines earlier this year after it was revealed that the company had collected millions of social media photos to provide facial scanning software.

The case was filed in the US state of Illinois. The state has one of the strictest laws in the United States regarding the use of biometric data, such as facial scans.

Clearview collects photos that are publicly available on social media to create a large database of faces. With the Clearview software, a user could provide an image of a person to find out their identity. Several companies, including Facebook, Twitter and LinkedIn, have asked Clearview to stop copying photos from users.

ACLU talks about a "privacy nightmare" and states that Clearview has used residents' fingerprints or facial scans without permission, which is illegal. Residents can sue companies for up to $ 5,000 per privacy violation.

"People cannot change their faces"

"Unbeknownst to the public, this company has offered a huge facial print database to private companies, police, federal agencies and wealthy individuals, allowing them to secretly track and target anyone with facial recognition technology," writes ACLU attorney Nathan Freed Wessler . "People can change their name and address to reflect their whereabouts and identities, but they cannot change their faces."

Research by BuzzFeed News previously showed that the software was used by private companies, even though the company said the software is only for authorities. The documents would indicate that Clearview also has or has had a customer from the Netherlands, but it is unclear whether it is a private or public party.

In early May, BuzzFeed News wrote that the company will stop supplying the software to private companies.