Last year, the US state department made an unusual request to a social network. It asked Twitter to delay maintenance that might have interrupted messages from Iranians protesting against the re-election of president Mahmoud Ahmadinejad. Twitter obliged by delaying its operation keeping the network open and Iranians free to tweet.

Anger over the Iranian presidential elections spilled onto the streets, along with violence as protesters fought with Iranian security forces. So, was this a Twitter moment? Did Twitter ignite the protests in Iran and abroad?

Not so fast, says Ethan Zuckerman, founder of the "citizen's media" website Global Voices Online. "A year after the fact people have tried very, very carefully to get a count of how many people were actually twittering from within Iran," he says. "And of those estimates, the estimates I find most reliable range from several dozen to a couple hundred."

According to Alec Ross, the senior adviser on innovation to US secretary of state Hillary Clinton, there is very little information to support the claim that Facebook or Twitter or text messaging caused the rioting or can inspire an uprising.

"What I have yet to see is a piece of data, a single piece of data, a single study that says, you know, access to information in environments of historic inter-cultural, inter-ethnic conflict has the following outcome when overlaid with a social media strategy," he cautions.

"The Internet is a wildly powerful and disruptive tool. It can be used for good, it can be used for ill. It disrupts markets, it disrupts communication, it changes the way people connect and collaborate with one another, but it's just a tool, and it's a tool used by people for a variety of different ends."

In other words, Ross says, social media may have some power, but like everything else, it has limitations.

With regard to the news out of Iran, Sanaz, an Iranian student studying in the US, says the social network websites at least helped get the news out about events after the election.

"It's absolutely crucial for people to be able to use these websites," says Sanaz, "because otherwise a lot of the news may not have gotten out, if the foreign journalists or Iranian journalists are banned or forbidden from doing their work".

Largely because these social media tools are so new, those who study its effects have more questions than answers about its influence on conflict and change.

"What we're really interested in is when someone comes up with a novel way of thinking and framing something," says Ethan Zuckerman, "not just how that quote spreads through time, but how that idea spreads through time."

Complicating matters, while analysts try to understand the uses and limits of social media, the technology keeps reinventing itself. That's especially true in developing countries, which in some cases have leapfrogged over cumbersome personal computers, instead using their phones as computers.

That's according to Colin Rule, who is eBay and PayPal's first director of online dispute resolution. "And these phones are getting smarter all the time," notes Rule. "So, they can do text messaging, they can do voice communication obviously, but they can also start to access parts of the web and as they get more and more powerful they'll be able to access more and more of the web."

This may nowhere be more true than in many African nations, where use of mobile phones and other portable devices is exploding.

Marc Lynch is an associate professor of international affairs at George Washington University. He says: "I think one of the things which we all grapple with as social scientists trying to deal with this is that it's implausible that this fundamental transformation in the way people process and receive information and the way information flows – it's implausible that this doesn't matter."

So what's the real world impact of social media? Can BlackBerrys and smart phones inspire demonstrations? Do Twitter, Facebook or YouTube make it easier or more difficult to organise large, diverse groups of people?

Answering that question, says Marc Lynch, remains "maddeningly difficult" and will for some time.

First posted on VOANews.com