Government forces retreated en masse from the onslaught, leaving behind a military hardware bonanza, including the U.S.-made armored Humvees as well as trucks, rockets, artillery pieces, rifles, ammunition, even a helicopter. Some of the seized materiel was old or otherwise non-functioning; but a lot was promptly put to use on the battlefield.
Pictures of grinning Islamist warriors cruising in U.S. Humvees bedecked with white-on-black militant flags flooded the Internet and became the signature image of the ISIS rampage.
ISIS social-media enthusiasts even mocked the global #BringBackOurGirls Twitter campaign, referring to girls kidnapped by an Al Qaeda offshoot in Nigeria. ISIS sympathizers began tweeting #BringBackOurHumvee.