Accounts associated with supporters of ISIS have used the social networks to spread misinformation by sharing video and images recorded in previous years in Iraq or in other countries, including Syria.

Charles Lister, a fellow at the Brookings Doha Center, pointed to a new claim on one of those accounts that the militants had executed hundreds of captured government fighters. The claim was impossible to immediately verify, but a day earlier, video posted on YouTube appeared to show a large number of soldiers being taken into custody by the insurgents.