How Islamic State Communicates With Followers

American-backed forces took control of Raqqa from the Islamic State group in mid-October. Terrorism experts say they believe the capture of the de facto capital of the group's self-declared caliphate could cause more guerrilla activity and attacks.

But the BBC, which monitors media activity worldwide, reports an unprecedented drop in Islamic State communications. Here & Now's Robin Young learns more from Mina Al-Lami (@Minalami), jihadi media expert at BBC Monitoring.