When a lone terrorist slaughtered 38 tourists at a Tunisian resort on June 26, the Islamic State turned to social media to claim credit and warn of more attacks on the world's nonbelievers.

U.S. authorities are still investigating whether the Thursday attack on a military recruiting center and a Navy support center is an act of domestic terrorism, but jihadist sympathizers on Twitter wasted little time declaring it one.

When a lone terrorist slaughtered 38 tourists at a Tunisian resort on June 26, the Islamic State turned to one of America’s leading social-media companies to claim responsibility and warn of more attacks on the world’s nonbelievers.

While the world is transfixed on ISIS, its scrutiny dangerously overlooks Iraq’s Shiite militias. The popular mobilization forces (PMF)—a collection of Shiite, Iranian-backed militias—liberated Tikrit in April and are providing the muscle in today’s...

The Obama administration is sending mixed messages over Twitter's emerging terrorism problem — how to deal with the Islamic State of Iraq and Syria and other extremist groups that use the social media giant's open platform to incite violence and...

Those keeping a close watch on jihadist threats and recruiting on social media sites say Twitter is largely ignoring calls to block tweets from Islamic extremists, and note that the famous social networking company has done little to stop accelerated...

"Islamic State" [IS] activists are "weaponizing Twitter; they're weaponizing social media," warns Ambassador Mark Wallace, one of the founders of the Counter Extremism Project (CEP), which launched in the US in September and is now expanding its...

Mark Wallace, president of the anti-extremism organization CEP, said that more than 40 thousand supporters of the extremist organization Daash are present on the social networking site Twitter.

Sometimes all it takes - is one sympathetic ear or voice in a massive sea of indifference to turn a law-abiding citizen into an agent of terror and mass destruction. Islamic State or ISIS continues to post 100,000 tweets daily in order to recruit...

The Islamic State’s deadly plots against Western targets are on the rise, spiking to 28 this year while the group is steadily expanding its supporter base in the U.S., according to a “Terror Threat Snapshot” circulated by Rep. Michael T. McCaul...