In a clear sign that al Qaeda is losing the ideological battle with ISIS, online forums once aligned with al Qaeda — including Osama bin Laden’s favorite chat room — have switched allegiance to the more violent Islamic State, experts say.

The trend is one of several “metrics” indicating al Qaeda has been stung by losses in leadership and prestige and is losing the internal war for loyalty among the most radical Islamists, say both terrorism experts and U.S. government officials, who’ve seen al Qaeda operatives shift loyalties, as well.

Evan Kohlmann of Flashpoint Intelligence, an NBC terrorism analyst, said there are 10 or fewer terrorist forums where the most battle-hardened jihadis gather, and the chat rooms have rigorous controls on who can post. Only one of these terrorist forums, according to Kohlmann, remains loyal to al Qaeda and its affiliates.

Kohlmann explained that the forums have secure areas where only “online couriers” from terror groups post official statements and tutorials and provide connections to like-minded individuals. All of those couriers were once loyal to al Qaeda.