The militant group the Islamic State of Iraq and the Levant (ISIS), a Sunni extremist group that has been waging an insurgency in Iraq, has also been fighting to make gains on social media.
Long before the group started seizing major Iraqi cities starting in early June, it had developed a vast social media presence including active Twitter accounts, a specialized app and several videos claiming to depict violence perpetrated by its members.
The group, which experts estimate has up to 5,000 members, has said that one of its goals is to see the formation of an Islamic state that straddles the Iraq-Syria border.
Here's a look at some of the ways ISIS uses social media to spreads its message, recruit members and create an environment of fear.
A number of Twitter accounts have been active in posting ISIS messages, photos and videos to their followers.
On June 15, images appearing to show the capture, transport and massacre of Iraqi soldiers by ISIS gunmen went viral after being shared extensively on Twitter by pro-ISIS accounts.
There are several Twitter accounts that tweet ISIS-related material.
App
Another tool ISIS used to expand its presence on social media was an Arabic-language app that was available for a period of time on the Google Play store.
The app, called "The Dawn of Glad Tidings" or "Dawn" for short, was an ISIS product that was advertised as a way to keep abreast of the latest news related to the group.
According to media reports, it was originally launched in April 2014.
Once users installed the app, it would automatically post ISIS material to the user's Twitter account. The app would post the same tweet to each user's Twitter account, spacing the tweets out so it could avoid alerting Twitter's anti-spam detectors.
At its peak, the app posted almost 40,000 tweets in a single day, when ISIS stormed the northern Iraqi city of Mosul, according to The Atlantic.
According to media reports, the app has been taken down from the Google Play store.
Videos
There are also several videos that have been posted online appearing to show violent executions performed by ISIS fighters.
In one particularly brutal video posted in mid-June, ISIS fighters appeared to enter the home of an Iraqi police chief. They blindfold him and eventually behead him, according to the Mirror.
Still images from the videos were later tweeted out with the chilling caption: "This is our ball. It is made of skin. #WorldCup." The authenticity of the video could not be independently verified.
Western University professor of media studies Tim Blackmore said that while the use of social media by extremist groups like ISIS can help spread its message, it can also cloud how powerful the group has actually become.
"The problem is that although ISIS looks stronger because of this, because they can get their message out further, they also look weaker because we don't know how big they actually are," he told CTV News Channel.
"Maybe they're creating a spin campaign…. and when we're faced with a spin campaign we know how to handle that: we switch off."