Al Qaida

Al-Qaida’s media arm has released an audio in which the purported son of the late al-Qaida leader Osama bin Laden threatens revenge against the U.S. for assassinating his father.

Al-Qaida’s branch in Syria has recruited thousands of fighters, including teenagers, and taken territory from government forces in a successful offensive in the north, illustrating how the cease-fire put in place by Russia and the United States to weaken the militants has in many ways backfired.

Law enforcement is trying to draw the line between sympathizers and terrorists, and the Internet is making it even harder to pin it down.