Two despots are gone, and others will be wondering who’s next.The departure of Egypt’s Hosni Mubarak, after weeks of defying his people and the world, came hard on the heels of that of Tunisian President Zine el-Abidine Ben Ali, whose flit to Saudi Arabia triggered a wave of popular discontent that continues to rock the Arab world.The causes of the unrest were familiar enough: poverty, corruption and ruthless suppression of dissent. What made the difference this time was the maturity of the internet – and social media in particular – as a tool for change.Frightened by widespread public protests that his soldiers and police thugs had failed to quell, Mubarak targeted the independent TV network Al Jazeera (english.aljazeera.net) as a troublemaker. The Qatar-owned network had broadcast the first images of protest in Tunisia, and Mubarak ordered it off the air in Egypt after it broadcast an interview with a leader of the banned Muslim Brotherhood.The move failed, because Al Jazeera was only one branch of a much larger media tree. Young, educated, tech-savvy Egyptians made widespread use of Twitter and Facebook to spread the word about protest rallies which eventually brought much of the country to a halt and finally told Mubarak the game was up, despite his efforts to shut down internet and mobile phone access.A reluctant hero of the uprising was Wael Ghonim, the regional head of marketing for Google, who spent 12 days in prison for helping to organise the Twitter and Facebook campaigns (see boxout for links about his story). "Organisation, networking, exposure to suppressed ideas and information, the habits of debate and self-empowerment in a culture of humiliation and conspiracy: These are some of the gifts social media is bestowing on overwhelmingly young populations across the Arab world,” wrote Roger Cohen in the New York Times.  Egypt’s Middle East neighbours are taking note: Jordan’s King has initiated political reform, while Syrian authorities have lifted a five-year ban on Facebook. Yemen, heavily dependent on US aid and facing a secessionist rebellion, is nervous – as is Algeria, where protests have met with violent clampdowns. Sudan, Egypt’s southern neighbour, is to be partitioned following a referendum in the south, and a ‘Facebook rebellion’ against strongman Omar al-Bashir is underway. Most encouraging, perhaps, has been the unity shown in Egypt between Islamists and secularists. Contrary to western fears, revolution may not mean fundamentalism. If social media have helped spread one philosophy, it is that of democracy.