The number of counterterrorism investigations has increased over the past decade, in part because technology provides law enforcement with leads, said Daniel Byman, a senior fellow at the Center for Middle East Policy at the Brookings Institution. Social media enables the FBI to locate suspects. Court records show that many ISIS probes begin with a review of Facebook profiles and Twitter feeds.
It takes time and resources for the FBI to weed through ominous internet posts and determine whether an individual is bloviating for shock value or if they're making true threats that need to be chased down, said Byman.
"You have a lot of people bragging on social media and that comes to the attention of authorities," said Byman.