How to Stay Alert This Holiday Season

The Department of Homeland Security is cautioning Americans to be on high alert this holiday season as the world is shaken by yet another attack. This time, authorities say, a lone wolf with mental health issues drove an SUV into a crowd of holiday shoppers, injuring 19 in Melbourne, Australia Thursday. Authorities say that the attacker did not have links to terror organizations. The attack comes just 10 days after a failed terror attack in a Manhattan subway tunnel.