MEMPHIS (AP) — A federal judge in Memphis has denied a request to modify a decades-old order barring the city from engaging in surveillance of protesters and activists.

U.S. District Judge Jon McCalla’s ruling Wednesday responds to a sealed motion by the city of Memphis seeking to change a consent decree issued in 1978. The decree followed disclosures that the Memphis Police Department had spied on civil rights activists, violating their First Amendment rights.

An American Civil Liberties Union lawsuit claims Memphis police engaged in improper electronic surveillance of activists associated with Black Lives Matter and other groups in recent years. McCalla has ruled the city has violated the order.

Memphis Mayor Jim Strickland has said the agreement can severely restrict the police department’s ability to “use modern technology to fight crime.”