China’s online community brimmed with disappointment - if not despair - on Tuesday after online media reported that Iran had granted its citizens access to Facebook and Twitter. Both sites had been walled off from Iranian users since 2009. This leaves China, along with its neighbour North Korea, among the very few countries which still block Facebook and Twitter. “Iranians are now returning to Facebook, yet we Chinese haven't even met Facebook,” one microblogger commented on Weibo.

Almost every major political figure has a social-media presence today. Chechen strongman Ramzan Kadyrov is an Instagram addict, as is Syria’s first family. Hugo Chavez was a prolific tweeter, and Fidel Castro blogs occasionally. Iowa senator Chuck Grassley live-tweets University of Northern Iowa Panthers women’s volleyball matches. Yet nobody’s quite as strange as Iran’s Supreme Tweeter, Ayatollah Ali Khamenei.

Twitter, Facebook, and other social networks are back online in Iran. It’s been four years since the government shut off access to most social media during protests following the 2009 presidential elections. But a new administration, elected in June, has vowed to improve communications in Iran and liberalize access to the internet. President Hassan Rouhani is himself on Twitter.

A hardline backlash always looms large over any attempt by a new government in Tehran to present itself as one that the West can talk to. President Hassan Rouhani has already found that the greatest challenge to public diplomacy is an apparent lack of discipline, rather than a lack of influential allies or favourable laws in a country where Facebook and other social networks are banned but not illegal.

With Twitter set to make its debut on American stock exchanges, a critical question looms: Can toppling dictators also be good business? Over the course of its seven-year history, Twitter has gone from scrappy, disorganized start-up to a heavyweight of the social media revolution. In the process, it's become much more than a business. From Tahrir Square to Gezi Park, Twitter has made itself indispensible to activists everywhere, providing a tool to decry abuse, organize protests, and help overthrow bad leaders.

Prime Minister Benjamin Netanyahu responded tepidly to Hassan Rohani's Rosh Hashanah Twitter greetings on Saturday, saying he is not impressed by "Greetings coming from the mouth of a regime that only last week threatened to eradicate the State of Israel." Netanyahu added that the Iranian leadership will be evaluated through its actions, and not via greetings "whose only goal is to divert attention from the fact that even after the elections, it continues the enrichment of uranium and the cunstruction of a plutonium reactor meant to allow it to develop nuclear weapons that will threaten Isr

In recent days, the blogosphere and the international press have been abuzz over the public relations campaign undertaken by Iran's new president, Hassan Rouhani, and his foreign minister, Mohammad Javad Zarif. Tweets by accounts associated with both men — caveat: the president has not explicitly confirmed his —can be credited with nudging Iran’s public posture on Syria in a more moderate direction, and distancing the new Rouhani administration from the anti-Semitic trope of his predecessor, Mahmoud Ahmadinejad.

In solidarity with victims of the 1973 coup in Chile, Amnesty International is calling for silence following the country's first goal in its match against Venezuela at National Stadium Friday. In 1973, days after the September 11 coup, about 12,000 suspected leftists were shepherded into the National Stadium, where they were interrogated and tortured...Thousands online are using #goldelsilencio ("silent goal") to discuss the campaign, causing "Chile" to trend worldwide.