Yet amid the noise and hoaxes there is always a strong signal, bringing valuable, important information to light. When a US Airways flight was forced to land on the Hudson River, a man on a ferry was the source of an urgent, eye-opening image that only a bystander could have captured at that moment: People on the ground are even more valuable in places where journalists have little or no access, and aid agencies have not been able to operate. Today, these witnesses and participants often reach for a phone to document and share what they see. It could be a bystander on a boat in a river - or a man who just walked away from a plane crash, as with this example from 2013: The public relies on official sources such as news organizations, emergency services and government agencies to provide credible, timely information. But, at the same time, these organizations and institutions increasingly look to the public, the crowd, to help source new information and bring important perspective and context. When it works, this creates a virtuous cycle: Official and established sources of information - government agencies, NGOs, news organizations - provide critical information in times of need, and work closely with the peo- 9