The app facilitated communications in a building where cell service is poor and personal phones are not allowed in some areas.

Defense Secretary Pete Hegseth used the Signal app on a personal computer in his office that was connected to the internet on an unsecured commercial line, what's known as a "dirty line," two sources confirmed to ABC News Thursday.

Defense Secretary Pete Hegseth used a “dirty line,” which refers to an unsecured internet connection, to connect to the Signal app on a personal computer in his office, multiple outlets reported. A Pentagon spokesperson denied that Hegseth used an unsecured connection in a statement to the Associated Press and added that the “use of communications