These stories are not simply sceptical about the contribution of social media,but determined to deny it has played any part.

Those at the vanguard of this argument include Malcolm Gladwell in theNew Yorker (Does Egypt Need Twitter?),theNew Statesman'sLaurie Penny (Revolts Don't Have to be Tweeted) and even David Kravets ofWired.co.uk(What's Fuelling Mideast protests? It's More Than Twitter).

All have argued one way or another that since there were revolutions before social media,and it is people who make revolutions,how could it be important?

Except social media has played a role. For those of us who have covered these events,it has been unavoidable. Precisely how we communicate in these moments of historic crisis and transformation is important.

The medium that carries the message shapes and defines as well as the message itself. The instantaneous nature of how social media communicate self-broadcast ideas,unlimited by publication deadlines and broadcast news slots,explains in part the speed at which these revolutions have unravelled,their almost viral spread across a region.

It explains,too,the often loose and non-hierarchical organisation of the protest movements unconsciously modelled on the networks of the web. Speaking recently toThe Huffington Post,Rosen argued that those taking positions at either extreme of the debate were being lazy and inaccurate.

''Wildly overdrawn claims about social media,often made with weaselly question marks (like:'Tunisia's Twitter revolution?') and the derisive debunking that follows from those claims ('It's not that simple!') only appear to be opposite perspectives.

In fact,they are two modes in which the same weightless discourse is conducted.

''Revolutionary hype is social change analysis on the cheap. Debunking is techno-realism on the cheap. Neither one tells us much about our world.''

Rosen is right. And when I began researching this subject I too started out as a sceptic. But what I witnessed on the ground in Tunisia and Egypt challenged my preconceptions,as did the evidence that has emerged from both Libya and Bahrain.

For neither the notion of the''Twitter Revolutions''or their un-Twitterness,accurately reflects the reality. Often,the contribution of social networks to the Arab uprisings has been as important as it also has been complex,contradictory and misunderstood.

Instead,the importance and impact of social media on each of the rebellions we have seen this year has been defined by specific local factors (not least how people live their lives online in individual countries and what state limits were in place).

Its role has been shaped too by how well organised the groups using social media have been. When Tarak Mekki,an exiled Tunisian businessman,politician and internet activist returned to Tunisia from Canada in the days after the Jasmine Revolution he was greeted by a crowd of hundreds.

Most of them know Mekki forOne Thousand and One Nights,the Monday-night video he used to post on YouTube ridiculing the regime of the fled President Zine Alabidine Ben Ali.

''It's amazing that we participated via the internet in ousting him,''he said on his arrival.''Via uploading videos. What we did on the internet had credibility and that's why it was successful.''

Tunisia was vulnerable - under the Ben Ali regime - to the kind of external and internal dissent represented byOne Thousand and One Nights.

In a state where the media were tightly controlled and the opposition ruthlessly discouraged,Tunisia not only exercised a tight monopoly on internet provision but blocked access to most social networking sites - except Facebook.

''They wanted to close Facebook down in the first quarter of 2009,''says Khaled Koubaa,president of the Internet Society in Tunisia,''but it was very difficult. So many people were using it that it appears that the regime backed off because they thought banning it might actually cause more problems[than leaving it].''

Indeed,when the Tunisian government did shut it down briefly,for 16 days in August 2008,it was confronted with a threat by cyber activists to close their internet accounts.

The regime was forced to back down. Instead,says Koubaa,the Tunisian authorities attempted to harass those posting on Facebook.

''If they became aware of you on Facebook they would try to divert your account to a fake login page to steal your password.''

And despite the claims of Tunisia being a Twitter revolution - or inspired by WikiLeaks - neither played much of a part. In Tunisia,pre-revolution,only around 200 active tweeters existed out of around 2000 with registered accounts.

The WikiLeaks pages on Tunisian corruption,says Koubaa,who with his friends attempted to set up sites where his countrymen could view them,were blocked as soon as they appeared - and anyway,the information was hardly news to Tunisians.

However,''Facebook was huge,''he says. Koubaa argues that social media during Ben Ali's dictatorship existed on two levels.

A few thousand''geeks''like him communicated via Twitter,while perhaps two million talked on Facebook. The activism of the first group informed that of the latter.

All of which left a peculiar loophole that persisted until December,when the regime finally launched a full-scale attack against Facebook.

This in a country that already tortured and imprisoned bloggers,and where the country's internet censors at the Ministry of the Interior were nicknamed''Amar 404''after the 404 error message that appeared when a page was blocked.''Social media was absolutely crucial,''says Koubaa.

''Three months before Mohammed Bouazizi burned himself in Sidi Bouzid we had a similar case in Monastir. But no one knew about it because it was not filmed. What made a difference this time is that the images of Bouazizi were put on Facebook and everybody saw it.''

And with state censorship rife in many of these countries,Facebook has functioned in the way the media should - as a source of information.

Around a week after Ben Ali's fall,I run into Nouridine Bhourri,a 24-year-old call-centre worker,at a demonstration in Tunis against the presence in the government of former members of the old regime.

''We still don't believe the news and television,''he says,a not surprising fact when many of the original journalists are still working.''I research what's happening on Facebook and the internet.''

Like many,Bhourri has become a foot soldier in the internet campaign against the old Tunisian regime.''I put up amateur video on Facebook. For instance,a friend got some footage of a sniper on Avenue de Carthage.

"It's what I've been doing,even during the crisis. You share video and pictures. It was if you wrote something - or made it yourself - that there was a real problem.''

If Twitter had negligible influence on events in Tunisia,the same could not be said for Egypt.

A far more mature and extensive social media environment played a crucial role in organising the uprising against Hosni Mubarak,whose government responded by ordering mobile service providers to send text messages rallying his supporters - a trick that has been replicated in the past week by Muammar Gaddafi.

In Egypt,details of demonstrations were circulated by both Facebook and Twitter and the activists'12-page guide to confronting the regime was distributed by email. Then,the Mubarak regime - like Ben Ali's before it - pulled the plug on the country's internet services and 3G network.

What social media was replaced by then - oddly enough - was the analogue equivalent of Twitter:handheld signs held aloft at demonstrations saying where and when people should gather the next day.

Sultan Al Qassemi,a columnist based in the United Arab Emirates who has tweeted non-stop on the uprisings,passing on information and English translations of key speeches,believes that some claims about the impact of social media need to be taken with a pinch of salt.

''Social media has certainly played a part in the Arab Spring Revolutions but its impact is often exaggerated on the inside. Egypt was disconnected from the outside world for days and yet the movement never stopped. I have missed work,I have missed sleep,I have forgotten to eat,I have strained my eyes,fingers and hands,I am not Tunisian,Egyptian or Libyan,but it's all been worth it.

''Today Libya is facing an even more severe internet disruption,yet we continue to see the movement picking up pace. Where social media had a major impact was conveying the news to the outside world,bloggers and Twitter users were able to transmit news bites that would otherwise never make it to mainstream news media.

''This information has been instrumental in garnering the attention of the citizens of the world who expressed solidarity with those suppressed individuals and may even put pressure on their own governments to react. Other uses for social media were to transmit information on medical requirements,essential telephone numbers and the satellite frequencies of Al Jazeera - which is continuously being disrupted.''

Indeed,this is what has been most obvious about social media's impact in Bahrain and Libya in the past week.

Social networking sites have supplied the most graphic images of the crackdowns on protesters,but also broadcast messages from hospitals looking for blood,rallied demonstrators and provided international dial-up numbers for those whose internet has been blocked.

Libyan activists also asked Egyptians to send their sim cards across the border so they could communicate without being bugged.

But above all it has been about the ability to communicate. Egyptian-born blogger Mona Eltahawy says that social media has given the most marginalised groups in the region a voice. To say'''Enough'and'This is how I feel.'''

In many respects,what people were doing on Facebook and Twitter was just what dissident bloggers had been doing in the run-up to the uprisings - often at great risk.

And in Tunisia under its old regime - as elsewhere - the consequences for blogging against the government's abuses could be extremely harsh. Zuhair Yahyaoui,the founder ofTunezine,an opposition website,was imprisoned,not least for publishing a letter written by his uncle,a judge,demanding an independent judiciary. Tortured and abused in prison,he died two years after his release,aged 37.

However not everything broadcast over social media sites has been either accurate or reliable. The unedited and unmediated nature of the stories that have been told have led to inaccuracies,which have sometimes proven beneficial to those opposing the regime.

One of these narratives - created right at the beginning - was the story of Bouazizi himself. The story of a university graduate forced to sell fruit who killed himself when he could not even do that proved to be incendiary. Except one of the key facts wasn't true. Bouazizi not only hadn't been to university,he had not even completed his school baccalaureate.

Video of a demonstration - claimed to be a recent gathering in Iran - and placed on social media sites was actually a protest that occurred in 2009.

The footage was unmasked as a fraud by Twitter users,ironically enough. But there has been another critical factor at work that has ensured that social media has maintained a high profile in these revolutions.

That is the strong reliance that mainstream media such as the Doha-based television network Al Jazeera has had to place on material smuggled out via Facebook,YouTube and Twitter.

This arrangement means that videos have often been broadcast back in to the country of origin - when Al Jazeera has managed to avoid having its signal blocked.

For me it is a phenomena best summed up by an encounter I had with a group of young Tunisians I met during a demonstration on the day after my arrival in Tunis.

I asked them what they were photographing with their phones.

''Ourselves. Our revolution. We put it on Facebook,''one replied laughing,as if it were a stupid question.

''It's how we tell the world what's happening.''

Guardian News and Media