Militants in Iraq threaten U.S. with new hashtag and why it matters

Lorenzo Franchesci-Bicchierai -- Mashable.com

The radical Islamist group sweeping through Iraq has a message for America: Stay out of this — or else.

And, in a modern update to the taped speeches of Osama bin Laden, the militants are using aTwitter hashtag to threaten the U.S.

The hashtag #calamitywillbefallUS is being used by the Islamic State in Iraq and the Levant (known as ISIL or ISIS,) a terror group that has shown extreme social media savvy.

Accounts linked to the group have been using the hashtag to make threats against the U.S. and spread ISIL propaganda.