A new Department of Defense manual shows that the U.S. government has broadened its interpretation of which citizens can be subject to physical or digital surveillance to incorporate homegrown terrorists.

Training slides created last year by the Air Force Office of Special Investigations (AFOSI) reveal that the U.S. now permits the collection of information about Americans for counterintelligence purposes “when no specific connection to foreign terrorist(s) has been established,” according to a report in Yahoo News on Tuesday.

The slides were obtained by Human Rights Watch, through a Freedom of Information Act request about the use of federal surveillance laws for counter-drug or immigration purposes, and shared exclusively with Reuters.

The previous Defense Department manual’s definition of counterintelligence activity, which was published in 1982, said the U.S. government must first demonstrate a target was working on behalf of the goals of a foreign power or terrorist group.

The updated Defense Department manual now refers to any target “reasonably believed to be acting for, or in furtherance of, the goals or objectives of an international terrorist or international terrorist organization, for purposes harmful to the national security of the United States.”

According to the training material, the shooting attacks in San Bernardino, California, in December 2015, and Orlando, Florida, in June 2016, are examples of “homegrown violent extremists.” The shooters declared their allegiance to ISIS shortly before or during the attacks, but investigators found no actual links to the murderous organization.

Michael Mahar, the Department of Defense’s senior intelligence oversight official, told reporters that AFOSI and other military counterintelligence agencies are permitted to investigate both active duty and U.S. civilian personnel as long as there is a potential case connected to the military. Investigations of civilians are carried out cooperatively with the Federal Bureau of Investigation.

Some former U.S. national security officials said the change is unlikely to have a significant impact on intelligence gathering. But privacy and civil liberties advocates who have seen the training slides disagreed, saying the change lacks sufficient oversight.

The updated interpretation was implemented with the realization that some people who do not have specific ties to a group such as ISIS or Boko Haram may still pose a significant threat, said Mahar.

“The internet and social media has made it easier for terrorist groups to radicalize followers without establishing direct contact,” he acknowledged. “We felt that we needed the flexibility to target those individuals.”