From Tweets in Egypt to blogs in Syria and Facebook campaigns in Sudan, the world has witnessed an unprecedented upsurge in citizen journalism, which played a major part in the 2011 "Arab Spring", a series of revolutions that saw long-term leaders in Egypt, Libya, Tunisia and Yemen deposed. But citizen journalists say social media's impact is not limited to political rabble-rousing and that it can also be a useful tool in humanitarian emergencies.
"Bloggers or citizen journalists are always within a community and have the advantage of being part of what is going on. If it is a protest, a blogger is part of that protest, if you have people marooned by floods, as a blogger you can relay that instantaneously, because you are at the centre of the action," said Raymond Palatino, a member of The Philippines House of Representatives and the South Asia editor for Global Voices, an international community of bloggers which recently held its annual media summit in the Kenyan capital, Nairobi.
He added that while mainstream media often reported on the news of a disaster, citizen journalists were able to provide valuable background information that could impact humanitarian policy. "Reporting a disaster or an emergency is as critical as reporting the events leading to it. How did people react just before it happened and so on," Palatino said.
He noted that while social media was gaining popularity, it remains more useful when used in conjunction with mainstream media than on its own. "Citizen journalism is complementary to mainstream media but they can never be competitors. They all have a role to play in their own way... In places of conflict, mainstream media organizations have relied heavily on bloggers to get information," he added. "Ours is to enrich what mainstream media or aid organizations have."
Faisal Kapadia, a Pakistani online social activist who co-founded SA Relief, a platform established in the aftermath of the 2005 Earthquake in South Asia to help coordinate and disseminate data on disasters in and around South Asia, says during emergencies, information needs to be transmitted using methods and language that is accessible to those affected.
"If everybody can't access a computer, a majority of people can access a mobile phone. Innovative ideas like transferring messages from platforms like Twitter into people's phones as SMS text messages and in a language they understand can help in times of disaster," he said. "During the  Pakistani floods for instance, we were able to track real-time the distribution of food. In humanitarian situations, we are able to ask people what they need in a language they understand and get that information to aid organizations or to the world."
Fundraising, psychological benefits
Social media has also been used to raise money for emergencies; a 2011 campaign started by a Kenyan Twitter user, Ahmed Salim, gained some popularity among internet users using the Twitter hashtag #FeedKE; a similar campaign, Kenyans for Kenya, raised over US$8 million through corporate sponsors and Mpesa, a mobile phone money transfer service run by telecoms firm Safaricom.
According to the authors of a 2011 study on the use of social media for humanitarian purposes, the "peer-to-peer" nature of social media offers psychological benefits to vulnerable populations.
"Disaster victims report a psychological need to contribute, and by doing so, they are better able to cope with their situation," they said. "Affected populations may gain resilience by replacing their helplessness with dignity, control, as well as personal and collective responsibility."
Anne-Marie Schryer-Roy, advocacy and communications officer at Adeso, a humanitarian organization working in the Horn of Africa, told IRIN, social media is becoming an important tool in the work of her organization. "One of social media's greatest attributes is the ability to have a two-way dialogue with the communities that are being affected by emergency situations. Communities can share updates about what is happening in real-time and about their pressing needs, which in turn can help inform our interventions," she said.
The study also pointed to a number of challenges for social media in the humanitarian field, including the tendency for public officials to view peer-to-peer communications as "backchannels" with the "potential to spread misinformation and rumour". In addition, in the absence of normal checks and balances that regulate traditional media, privacy rights violations can occur as people use social media to describe personal events and circumstances.
Another challenge is the possibility of loss of mobile phone signal or Internet access during major disasters, effectively cutting off social media communication.
Kapadia noted there was still much to do to ensure that social media made a real impact on humanitarian assistance during disasters. "It is important to interrogate why the impact is at times never felt," he said.
Adeso's Schryer-Roy said it would be important to address the issue of high volumes of unverified information being transmitted via social media to ensure it could be used more effectively. "There is need to harness social media to better serve humanitarian interests, especially in developing countries where affected populations might have little access to it," she said. In Ethiopia, for example, with a population of close to 85 million, just 8 percent of people have access to a mobile phone.
"We need to find ways to ensure we involve those populations and tailor our communications based on their needs. In the end, it will help us improve how we deliver humanitarian assistance," she added.