A former White House Homeland Security Advisor is convinced that these sites have become a safe haven for terrorist organizations like ISIS to spread their message and recruit violent jihadists. Having spent more than two decades in the field of global terrorism, Frances Townsend, former Homeland Security Advisor to President George W. Bush and now head of the Counter Extremism Project, has witnessed just about everything imaginable when it comes to the subject. But most recently, it is what she's witnessing on Twitter that has her greatest attention.— and concern.