AFTER the brutal murder of Lee Rigby, a British soldier, in London on May 22nd, many viewers watched a video of one of his suspected killers, with bloodstained hands and a meat cleaver, addressing onlookers. The video was broadcast first on ITV News, a British network, which dozens of media firms then credited. But that video was not a piece of professional journalism. It was shot on a BlackBerry by a man on his way to a job interview. Shortly after the killing, ITV sent journalists and producers to the scene. The man shared his video but asked to remain anonymous.

Many feared that social media would undermine professional reporting. Defensive journalists derided it. “I would trust citizen journalism as much as I would trust citizen surgery,” quipped Morley Safer, a CBS correspondent. As it turns out, photographs, videos and tweets from ordinary people are improving and expanding news coverage. They also create work for journalists who know how to curate, authenticate and analyse their material.

Far from shunning “shaky footage”, audiences think users’ videos more intimate and authentic than broadcasters’ slick shots, says Claire Wardle of Storyful, a firm that spots and verifies user-generated content. “If they don’t show it, people will go to YouTube to see it.” Journalists covering big news stories are getting better at scouring social networks for sources. And thrusting news firms have tried to outdo their competitors by building systems that encourage readers to submit material to them directly.

CNN’s iReport is among the oldest of these; it now has 1.3m contributors, up sixfold since its launch in 2008. Aftonbladet, Sweden’s most popular newspaper, asks readers to register their location, alerts them when big news breaks nearby, and offers to publish their most striking photographs or videos in exchange for a small fee. In April the Guardian, a British newspaper, launched Guardian Witness—a minisite backed by EE, a telecoms firm, that helps mobile users share newsworthy videos. Alan Rusbridger, the Guardian’s editor, expects more firms to “create mechanisms to increase the ease with which people can file to them.”

But witnesses are getting harder to seduce and keener to post directly to social networks. In 2005 nearly all of the BBC’s user-generated content was submitted directly to the organisation; now it has to hunt down half of it from social networks. That means sifting a lot of dross. Every day 7,000 hours of news-related videos are uploaded to YouTube, an online-video site owned by Google, much of it created by amateurs. News organisations are hiring ever bigger teams to scavenge for the best. BBC News has one of the largest social media departments, with around 20 full-time employees; most big newspapers have a team of between five and seven people. Slick tools quicken the drudgery. Geolocation services such as Geofeedia and Banjo, for example, let journalists search for social media posted from specific locations, accurate to a single city block.

Whatever they find, reporters must confirm the material’s veracity—just as they would with a traditional source. Outlets that rush this can run into trouble. CNN, the New York Post and others ran headlines about the Boston marathon bombing that later proved false, probably because speculation had been fuelled on Twitter and Reddit, a social news site.

Conscientious reporters will examine users’ past posts to see if they have obvious political biases and to check that they are where they claim to be. They use Google’s satellite maps to certify the location of a photograph or video, and search image banks to ensure that a photograph is not doctored. Local knowledge from a paid correspondent can ease the task. Two years ago editors at Associated Press discarded a video which purported to show fighting in Daraa, Syria. Eric Carvin, the firm’s social-media editor, says it showed a statue of Hafez Assad, a former Syrian president, which had been knocked down two weeks before.

Journalists who clear these hurdles must still get permission to use the material they have found. That can be a bigger challenge, says Liz Heron, director of social media and engagement at the Wall Street Journal. Usually its author will ask to be credited, but demand no payment. They are sometimes hard to track down, however, and newshounds lose valuable time waiting for replies. Many journalists want to see simpler licensing rules. They would like YouTube and Twitter to make it easier for web users to grant rights to news firms—perhaps by ticking a box when they first upload their content.

In the meantime, a clutch of new companies aim to make things more efficient. Storyful speedily tracks down, verifies and obtains the rights for user-generated content. Clients gain access to this by paying a monthly subscription fee of between $750 and $15,000. Citizenside, a French firm, is one of several sites that help citizen journalists sell exclusive stories to large networks. In 2011 it sold widely viewed footage of John Galliano, a British fashion designer, insulting patrons of a restaurant in Paris.

For the time being, images and videos make up most of the amateur journalism featured on mainstream media. Recording a video with a mobile phone or tweeting what you have just seen requires less effort and expertise than longer commentary. Jay Rosen, a professor of journalism at New York University, calls this use of amateur material by news organisations “networked reporting”. At the new frontier, he thinks, investigative journalists are making better use of amateur sleuths by requesting documents, testimonials and a spare hand. Every journalist needs help shovelling for dirt.

Correction: An earlier version of this piece misidentified the subject of a Syrian statue. The monument depicted Hafez Assad, not his son Bashar. Sorry.