The digital revolution has had a massive impact on the practice of foreign policy, revealing challenges and opportunities for modern diplomacy. But where is the line drawn between confidentiality and transparency?

One of Britain’s highest-ranking intelligence officials on Tuesday castigated the giant American companies that dominate the Internet for providing the “command-and-control networks of choice for terrorists and criminals” and challenged the companies to find a better balance between privacy and security.

The Internet has become so integral to economic and national life that government, business, and individual users are targets for ever-more frequent and threatening attacks.

A day after President Dilma Rousseff squeaked out a close electoral victory, Brazilian voters vented their frustrations one way they know best: on social media.  Online debates between supporters of the president and her unsuccessful rival Aécio Neves were hostile, in a country with one of the world’s deepest penetration of social-media use.

“It is only when we contest (ISIS') presence online, deny the legitimacy of the message it sends to vulnerable young people and expose (ISIS) for the un-Islamic cult of violence it really is ... that (ISIS) will truly be defeated,” Allen said.

The United States is pressing Arab nations and other allies to do more to counter the Islamic State group's slick propaganda campaign, with a top American envoy on Monday describing efforts to combat the extremist messages as a vital pillar in the fight to defeat the group.