The American Civil Liberties Union of Massachusetts (ACLU) filed a complaint on Thursday seeking more transparency from the FBI over its use of facial recognition software. The ACLU filed a Freedom of Information Act (FOIA) request about the use of the software, but the Department of Justice did not respond to the request. The ACLU alleged that this is a violation of the FOIA.

The ACLU is concerned about the civil rights and civil liberties implications of the federal government’s use of face recognition and other biometrics to track, identify, and monitor people. If implemented, these capabilities would threaten to grant the government an unprecedented power to pervasively track people’s movements and associations in ways that threaten core constitutional values.

The FBI has operated a Facial Analysis, Comparison, and Evaluation Service since 2015, along with a Next Generation Identification-Interstate Photo Service that allows law enforcement agencies to search a database of photos. The FBI is also in the process of “purchasing and/or developing additional biometric identification technologies that include not only face recognition, but also voice prints, and other forms of biometric identifications.”