If Facebook didn't start the Arab Spring it certainly helped accelerate the uprisings. Now the social network's role in toppling regimes has catapulted Mark Zuckerberg into the Forbes list of the 10 most powerful people on the planet.
The Facebook founder, 27, is the fastest riser in the business magazine's annual ranking of the "70 Most Powerful People In The World", soaring from number 40 to nine.
President Obama returns to the top of the list, displacing the Chinese President Hu Jintao, who also falls behind Vladimir Putin, the resurgent Russian Prime Minister.
The phone-hacking scandal has taken the lustre off politicians and media moguls. David Cameron falls three places to number 10, with Forbes citing his association with Andy Coulson, the No 10 communications director who quit after claims that he knew about hacking when editor of the News of the World. Rupert Murdoch, the News Corporation CEO who closed down the News of the World and saw his bid to control all of BSkyB collapse, tumbles down the list from 13 to 24.
New entries in the list include Wen Jiabao, the Chinese premier at 14, Opec's president Rostam Ghasemi at 32, and Christine Lagarde, the new IMF managing director, at 39.
Ms Lagarde's predecessor Dominique Strauss-Kahn, who resigned amid sexual assault charges, drops out of the list, along with Julian Assange and Oprah Winfrey. Tim Cook, the new Apple CEO, arrives at 58; his predecessor, Steve Jobs, was at 17 before his death.
The Forbes panel, which included the former US Treasury Secretary Larry Summers, assessed four factors: how many people they have power over; the financial resources they control; if they have influence in more than one sphere; and how actively they wield their power to change the world.
Mr Zuckerberg, worth $17.5bn (£11bn), displaced statesmen and media moguls because of the social influence wielded by Facebook, which now has 800 million users. A dinner guest of President Obama, he is following the philanthropic example of Bill Gates, giving $100 m to improve US schools.
Mr Gates rises to number five, with Forbes arguing the Microsoft chairman is "changing the world again through vaccines". The $28bn given away by the Bill and Melinda Gates Foundation is "saving millions of lives", the magazine said. Two criminals made it into the list: Joaquin Guzman Loera, 55, head of the Sinaloa drug cartel in northern Mexico, and Dawood Ibrahim Kaskar, 57, head of a Mumbai crime syndicate.
The Forbes power-wielders
Most powerful media mogul: Rupert Murdoch
Despite a terrible year in which a hacking scandal at the News of the World led to him dropping 11 places, Rupert Murdoch (24) remains the top dog in the media industry.
Most powerful criminal: Joaquin Guzman Loera
Described by one US drug enforcement official as more powerful than Pablo Escobar, drug trafficker Joaquin Guzman Loera (55) is the world's most wanted man, with an estimated wealth of $1bn.
Most powerful in sport: Sepp Blatter
The head of FIFA is not the only person in the list whose organisation is facing allegations of corruption, but Sepp Blatter (63) remains the most powerful person in sport.
Most powerful woman: Angela Merkel, German Chancellor
Forbes described Merkel (4) as "the de facto leader of the European Union".
Highest newcomer: Christine Lagarde
The first woman to run the IMF, Christine Lagarde (39) inherits an institution in crisis, overseeing multibillion-euro bailouts of Greece, Ireland and Portugal.
Most powerful octogenarian: King Abdullah bin Abdulaziz al Saud
At 87, the Saudi King (6) is the oldest person on the list, and the most powerful of the five octogenarians that populate the list.
Most poweful religious leader: Pope Benedict XVI
As spiritual leader to 1.2 billion Catholics around the world, the Pope (7) "delivers the final word" to his followers on abortion, gay marriage and female priests.
Most powerful in the southern hemisphere: Dilma Rousseff
The President of Brazil, an emerging economic powerhouse, Dilma Rousseff (22) is the third most powerful woman in the world and the most powerful person in the southern hemisphere.
Biggest climber and youngest: Mark Zuckerberg, Facebook CEO (40)
Mark Zuckerberg (9) is the youngest person on the list at age 27, and also the biggest climber, jumping 31 spots from 40th in 2010. Forbes justified his position for having done in seven years what the CIA failed to do in 60: "knowing what 800 million people think, read and listen to."
Most fashionable face: Bernard Arnault
The chairman of Louis Vuitton Moet Hennessy (65) is the fashion industry's sole representative in the list.
The top 10
1. Barack Obama (2010: No 2)
2. Vladimir Putin (3)
3. Hu Jintao (1)
4. Angela Merkel (4)
5. Bill Gates (10)
6. King Abdullah (3)
7. Pope Benedict XVI (5)
8. Ben Bernanke (8)
9. Mark Zuckerberg (40)
10. David Cameron (7)