Federal officials are holding a hearing Wednesday on terrorists' use of social media in the aftermath of the deadly May 3 shooting at a Prophet Muhammad cartoon contest in Garland.
In the House hearing, "Terrorism Gone Viral: The Attack in Garland, Texas and Beyond," U.S. intelligence officials are warning about the growing use of encrypted communication and private messaging by supporters of the Islamic State.
Chair of the House Committee on Homeland Security Michael McCaul (R-Austin) chaired the meeting set for Wednesday morning. John J Mulligan, Deputy Director of the National Counterterrorism Center, Francis X. Taylor, Undersecretary, Intelligence and Analysis at the U.S. Department of Homeland Security and Michael Steinbach, Assistant Director, Counterterrorism Division of the FBI and U.S. Department of Justice testified at the meeting.
The officials told a House committee on Wednesday that such modes of communications are complicating law enforcement efforts to keep tabs on extremists and terror suspects.
John Mulligan, the deputy director of the National Counterterrorism Center, said in his prepared remarks that one of the two men involved in an attempted terror attack in Garland, Texas urged fellow Islamic State supporters before the shooting to move their communications to private Twitter messages.
"The ISIS-inspired terror attack in Garland, Texas, demonstrated that terrorism is going viral," the committee said in a statement. "This hearing will examine the increasing threat from violent Islamist extremists groups, like ISIS, who use the Internet and social media to recruit fighters, share propaganda, and inspire and potentially direct attacks."
Federal authorities were tracking the Twitter account linked to 31-year-old Elton Simpson of Phoenix before he and another gunman opened fire Sunday in the Dallas suburb of Garland, said McCaul, who was briefed on the investigation by federal law enforcement officials.
The Department of Homeland Security and the FBI also had issued a joint intelligence bulletin April 20 to local law enforcement warning that the Garland event was a possible target for a terrorist attack, according to a DHS official who was not authorized to be quoted discussing the document.