According to NSA leaker Edward Snowden, the U.S. National Security Agency has a cyberwarfare program that hunts for foreign cyberattacks and is able to strike back without human intervention.

Called MonsterMind, the NSA cyberwarfare program, uses software to look for traffic patterns indicating possible foreign cyberattacks. This was revealed in a lengthy profile in Wired.

According to the Wired story, MonsterMind could automatically block a cyberattack from entering the U.S., then retaliate against the attackers.

Snowden told Wired: “These attacks can be spoofed. You could have someone sitting in China, for example, making it appear that one of these attacks is originating in Russia. And then we end up shooting back at a Russian hospital. What happens next?”

“If we’re analyzing all traffic flows, that means we have to be intercepting all traffic flows,” he said. “That means violating the Fourth Amendment, seizing private communications without a warrant, without probable cause or even a suspicion of wrongdoing. For everyone, all the time.”

A program such as Snowden described would raise major concerns, the American Civil Liberties Union said.

“The government has used excessive secrecy to prevent real debate over the wisdom and legality of many of its most sweeping surveillance programs,” Alex Abdo, an ACLU staff attorney, said by email. “This newly described program is just another example of that secrecy. If the government truly is scanning all internet traffic coming into the United States for suspicious content, that would raise significant civil liberties questions.”