The self-declared Islamic State has posted names, photos and what it says are addresses of 100 U.S. military personnel, calling on its supporters to "deal" with them.
The extremist group's so-called "hacking division," says the individuals have been part of efforts to defeat ISIS in Syria, Iraq and Yemen.
It says it has decided to release the information about the U.S. servicemen and servicewomen so "brothers in America can deal with you."
NPR has learned that the Department of Defense is investigating the threat but that officials believe the information was gleaned from public sources and does not represent a breach of government servers.
"It appears the list is people who are active on social media or who have spoken to press," a DOD official tells NPR.
As NPR's Dina Temple-Raston notes, several months ago the FBI and Pentagon asked military personnel to take identifying material off the web in anticipation of just such a possibility.
Dina says that defense officials also say that some of the personnel on the list had nothing to do with strikes against ISIS.
The New York Times adds that one example of this is the inclusion of B-52 bomber crew members stationed in Louisiana and North Dakota. B-52s, the Times says, have never been used in the anti-ISIS campaign.
"Several women are included on the list, but their faces in the photos were blurred. One of the photos appears to be at an official meeting with President Obama," the Times says.