Thanks to the rise of social media, news is no longer gathered exclusively by reporters and turned into a story but emerges from an ecosystem in which journalists, sources, readers and viewers exchange information. The change began around 1999, when blogging tools first became widely available, says Jay Rosen, professor of journalism at New York University. The result was "the shift of the tools of production to the people formerly known as the audience," he says.(41) ______.At first many news organisations were openly hostile towards these new tools. In America the high point of the antagonism between bloggers and the mainstream media was in late 2004, when "60 Minutes", an evening news show on CBS, alleged on the basis of leaked memos that George Bush junior had used family connections to win favourable treatment in the Air National Guard in the 1970s. (42) ______ CBS retracted the story and Dan Rather, one of the most respected names in American news, resigned as the show’s anchor in early 2005.(43) ______ Newspapers and news channels have since launched blogs of their own, hired many bloggers and allowed readers to leave comments. They also invite pictures, video and other contributions from readers and seek out material published on the Internet, thus incorporating non-journalists into the news system.(44) ______ "We see these things as being highly complementary to what we do," says Martin Nisenholtz of the New York Times. Many journalists who were dismissive about social media have changed their tune in the past few months as their value became apparent in the coverage of the Arab uprisings and the Japanese earthquake, says Liz Heron, social-media editor at the New York Times.Rather than thinking of themselves as setting the agenda and managing the conversation, news organisations need to recognise that journalism is now just part of a conversation that is going on anyway, argues Jeff Jarvis, a media guru at the City University of New York. (45) ______. All this requires journalists to admit that they do not have a monopoly on wisdom. "Ten years ago that was a terribly threatening idea, and it still is to some people," says the Guardian’s Alan Rusbridger. "But in the real world the aggregate of what people know is going to be, in most cases, more than we know inside the building. "[A] Journalists are becoming more inclined to see blogs, Facebook, Twitter and other forms of social media as a valuable adjunct to traditional media (and sometimes a corrective to them).[B] The role of journalists in this new world is to add value to the conversation by providing reporting, context, analysis, verification and debunking, and by making available tools and platforms that allow people to participate.[C] By providing more raw material than ever from which to distil the news, social media have both done away with editors and shown up the need for them.[D] This was followed by a further shift: the rise of "horizontal media" that made it quick and easy for anyone to share links (via Facebook or Twitter, for example) with large numbers of people without the involvement of a traditional media organisation. In other words, people can collectively act as a broadcast network.[E] With a single click of a Facebook "Like" button, for example, you can recommend a story, video or slideshow to your entire network of friends.[F] Bloggers immediately questioned the authenticity of the memos. A former CBS News executive derided blogging as "a guy sitting in his living room in his pyjamas writing what he thinks". But the bloggers were right.[G] But in the past few years mainstream media organisations have changed their attitude. The success of the Huffington Post (博客网站), which launched in May 2005 with a combination of original reporting by members of staff, blog posts from volunteers (including many celebrity friends of Arianna Huffington’s, the site’s co-founder) and links to news stories on other sites, showed the appeal of what Ms Huffington calls a "hybrid" approach that melds old and new, professional and amateur. 44