London 2012 has been the Olympics at which athletes have held control of their own coverage in the palm of their hands.

More and more, athletes have been using social media, like Twitter, Facebook and YouTube, to tell their fans about all the important - and less important - things in their lives. The platforms offer new opportunities for self-promotion.

Soon after his enthralling sprint for gold over 100 meters, Usain Bolt celebrated with his fans on FaceBook and Twitter - publishing a photo of his successful sprint as well as a few trademark, self-confident comments.

The reactions came in like a flash.

"Amazing, Usain! Surely you are the greatest of all times," a fan said on Twitter. And Bolt promptly retweeted the comment to his 984.000 followers.

Leaving nothing to chance

Four years ago at the Olympics in Beijing, Facebook and Twitter were regarded as a niche phenomenon - they were a minor issue for the International Olympic Committee (IOC).

This year in London, however, things are very different.

In preparation, the Games organizers created their own platform - the Olympic Athletes' Hub. It bundles Facebook comments and tweets from many of the athletes.

But the IOC has left nothing to chance. It drew up four pages of guidelines to govern the athletes' use of social media.

Athletes are forbidden to publish audio and video of their events. All comments have to be written as first person diary entries. And advertising on behalf of sponsors has also been strictly prohibited.

Most athletes have stuck to the IOC's rules. They have supplied fans with photos of medals, thanked them for cheering them on, or bemoaned their own failure.

But social media has proved to be a law unto itself - it cannot be controlled as easily as the IOC would hope.

In the first week of the Olympics, Twitter was the social media of choice for athletes who wanted to complain about their experiences in London. Social media was also the conduit for scandal.

Upon arriving in London, some athletes used Twitter to complain about an "odyssey" they had been forced to endure while travelling by bus to the Olympic village in East London.

Then, a Greek triple jumper published a racist slogan and a football player from Switzerland allegedly incited hatred against an opponent - they both had to leave.

In the US, some athletes also protested against the advertising ban.

Control where possible

There is no way for the IOC to keep total control of the thousands of tweets and Facebook comments that have been posted.

Instead, it has tried to create such a positive buzz about the Olympic Athletes' Hub that any negative news is blasted out of significance.

But this brave new world of social media means the next Olympics in 2016 will have an even greater task on its hands.

While Britain's national broadcaster has attempted to offer audiences full coverage of the Olympics for the first time - of every event on more than 20 channels - the feeling is that traditional radio and TV are out. And mobile distribution is in.