Facebook claims it has aggressively targeted terrorist content, eliminating 99 percent of terror-related messages before anyone even reports it. But the 90-page report from the Counter Extremism Project, entitled “Spiders of the Caliphate,” lays out the shortcomings in Facebook’s approach, and how ISIS supporters avoid detection by using Facebook Live to host meetings and linking to banned material in comments, tricks that avoid Facebook’s automated flagging tools. Even worse, the report shows how Facebook’s algorithmically-powered “recommended friends” feature is helping connect disparate groups of ISIS supporters across the globe.