PHOENIX -- The takeover of Iraq has been happening quickly.
But just who, exactly, is terrorizing Iraqi cities?
They are a militant group of Sunni insurgents known as ISIS, or the Islamic State of Iraq and Syria, according to ABC News. They are led by an Iraqi cleric and trying "to form an independent state with territory in Iraq, Syria and parts of Lebanon."
ISIS controls cities on both sides of the Iraq-Syria border. When weapons were seized from Mosul on Monday, they were able to move the weapons quickly. They also too over $400 million from Mosul city banks.
And even al-Qaeda's leader has disavowed them as being "too extreme."