The use of Twitter hashtags is just one part of an increasingly sophisticated social media campaign by ISIS as it seeks to capitalise on its dramatic territorial gains in recent days and establish a puritanical Islamic state or "caliphate" across a swathe of Sunni-majority Iraq.
The militants have developed an Arab-language Twitter app which updates users on the latest ISIS developments but also requires signatories to surrender a large amount of personal data and gives the terror group the power to send tweets from that individual's account.
Charles Lister, a terrorism expert at the Brookings Doha Centre, said the ISIS had developed an "all-encompassing" media strategy which was allowing it to outperform longer-established extremist groups in its search for recruits and publicity.
He said: "The slick nature of ISIS media releases has undoubtedly allowed it to become somewhat the 'celebrity' actor within the international jihadist community. On social media, not a day goes by without a foreign supporter - from London, to Mogadishu, to Manila - expressing their support and allegiance to ISIS's cause."
Twitter and other social media providers have shut down a number of ISIS-affiliated accounts in recent days under rules which ban the use of threatening language and racial or religious hatred. But new accounts quickly take their place.
One account, @Alnhim, this weekend tweeted a link to the recruitment video entitled "There Is No Life Without Jihad", featuring three Britons including Cardiff medical student Nasser Muthana, with seven World Cup-related hashtags.
With disenfranchised or disillusioned young Muslim men a priority for ISIS and similar groups when it comes to recruiting in the west, the harnessing of football-related tweets to its messaging strategy would seem to be a deliberate attempt to reach its target audience via their likely interests.
But ISIS propagandists, who last weekend announced an attempt to gain one billion supporters for an Islamic state on social media, are also determined to simply reach as wide an audience as possible.
An analysis of social media tactics being used by the group by The Atlantic magazine last week found it was using an Arabic language twitter account - @ActiveHashtags - which advertises the most popular hashtags to get its own material on the feed. When this happens, ISIS receives on average 72 retweets for every tweet it sends.
- UK Independent