Cameras are everywhere capturing headline events, from the worst atrocities in Syria to the tragic unfolding of Drummer Rigby's death in Woolwich. The proliferation of smartphones and social media means that the first instinct of many bystanders is to give rolling commentary on live events by posting footage, images and tweets online. And the mainstream media are only too keen to use their content. After all, what images and accounts would we have of 9/11 or the Arab Spring if these extraordinary events had not been so widely documented by ordinary members of the public? Citizen journalism brings us closer to the action and deepens our understanding of world events. It also empowers the public to play their part in major stories and to give voices to those who might otherwise not be heard.But are these 'karaoke journalists' playing an important role in the delivery of news, or are they, as their critics claim, naively gathering unfiltered, extremist views and actions? Why should we trust what they film when they have no formal training? And would their efforts sometimes be better spent helping someone in need? What legal, ethical and editorial responsibilities should the mainstream media consider when they choose to feature, edit or ignore user generated content?In this debate, from Intelligence Squared in partnership with ITV News, we will be asking, does citizen journalism have a valuable part to play in the dissemination of news or is it inevitably a risky business and likely to compromise truth? Is it a complement to mainstream media or a threat to traditional forms of journalism?