The father of a victim of the Islamic State's deadly attacks on Paris last year is suing Facebook, Google and Twitter for aiding the terrorist group. "Social networks have long stressed they will help legitimate investigations of crimes and attacks, but have resisted efforts to police or censor the vast amounts of content flowing through them," Counter Extremism Project CEO Mark Wallace said. "But social media groups are capable of doing more to prevent and remove horrific content from being streamed worldwide."