Mike McCaul: Lone Wolf Terrorism ‘a Very Hard Thing to Stop’

MCCAUL: "Well, I think the biggest concern that the FBI has and Homeland Security officials have is that we have gone beyond the days of bin Laden, where they were caves and couriers, to a new generation of terrorists who use the Internet through Twitter accounts to activate followers in the United States. These recruiters out of Syria are very sophisticated on the Internet, and through their Twitter accounts, and they have thousands of followers online in the United States, can send a call to arms to activate them to attack, in this case, police officers, in the Boston case, in Garland, or military installations as well. This is a very hard thing to stop, and a hard thing for FBI and Homeland to monitor. When you talk about the new wave of terrorism, this is pretty much it."