The importance of social media to the Orlando terrorist

From CNN we learn that Omar Mateen searched Facebook during his three hour attack at the Pulse nightclub in Orlando. He searched "Pulse Orlando" and "shooting." He also sent text messages to his wife asking what the news media was reporting. She never bothered to call police. He even posted on Facebook: "NOW TASTE THE ISLAMIC STATE VENGEANCE" AND "IN THE NEXT FEW DAYS YOU WILL SEE ATTACKS FROM THE ISLAMIC STATE IN THE USA."