It’s time for Twitter to step up. The micro-blogging site has refused to stamp out the considerable presence of terrorists on its network. Whereas Facebook is open to discussions of counterterrorism measures, Twitter’s response has been different. “The response we’ve gotten from Twitter is dismissive to the point of dereliction,” said Mark D. Wallace, CEO of the nonprofit think tank Counter Extremism Project, in recent testimony before Congress. “We have written three letters describing the problem and requesting a sit-down between Twitter and CEP leadership. Twitter has ignored all but one letter, and its reply, simply put, was indifferent at best.”