Yet in war, just as in nature, every action merits an opposite reaction. Over the past few years, many new forces have marshaled to engage ISIS in this war of social media. The United States has launched a constellation of social-media accounts to battle ISIS misinformation, while spies map ISIS networks through what they reveal of themselves online (one U.S. air strike was even guided in by an oversharing jihadist). Outside government, social-media companies have increasingly revised their own systems and terms of service in an effort to mop up terrorist accounts before they spread, as with Twitter's recent ban of all "indirect threats of violence." Hacker and independent activists are also playing an increasing role. Many associated with the hacking collective Anonymous, have taken to patrolling the darker places of the Internet, waging their own private fight to take down ISIS content wherever it is found. Some of them even named today, December 11, ISIS Trolling Day, an event dedicated just to making fun of the group.