A man claiming to be the self-appointed caliph of the Islamic State jihadist group made what is thought to be his first taped appearance in a video that circulated on social media Saturday.  Previously there were only two known images of the notoriously elusive Abu Bakr Al Baghdadi.

Prime Minister Narendra Modi has permitted Twitter unprecedented access to his administration in a drive to put social media at the heart of government, the US Internet company said.  Modi deployed an army of supporters over Twitter and Facebook during his successful election campaign.

Twitter has become an indispensable diplomatic networking and communication tool. According to the new study Twiplomacy, more than half of the world’s foreign ministers and their institutions are active on the social networking site. Here are five lessons from our world leaders on Twitter.

Unfortunately, there’s a long history of terrorism. Palestinians regarded it as a resistance to what they see as an illegitimate occupation. Of course, Israelis regarded it as terrorism. What I think is new here, which is very troubling, is that people are using the new tools of technology, social media, and you're beginning to see radical fringe elements that are able to organize, galvanize support.

As negotiators from Iran and the P5+1 nations meet behind closed doors in Vienna in a final push for a comprehensive nuclear deal, a separate round of negotiations is taking place online. Secretary of State John Kerry and his Iranian counterpart, Foreign Minister Javad Zarif, traded accusations, praise, and hopeful words in advance of the final round of nuclear negotiations. The two sparred in a pair of op-eds published in the The Washington Post (Kerry) and Le Monde (Zarif), and in a video Zarif made available on YouTube. 

In the wired age, "Twitter bombs" that spam feeds with militant propaganda are as much a part of the modern jihadi’s arsenal as bullets. But with every burst of online messaging from extremists comes potential blowback.