Key differences between Islamic State's claim of responsibility for the New York City truck attack and claims for previous terror attacks have caught the eye of counterterror officials, who are trying to determine what it might mean for the state of terror group. "The al-Naba story on the New York attack relies exclusively on outside media reporting of the attacks," according to an analysis done by Ryan Pereira for the Counter Extremism Project. "Traditionally, Amaq and al-Naba claims for responsibility include language suggesting that a source close to Amaq or a source close to the Islamic State relayed attack details to the group's media officials," Pereira wrote.