A VIDEO SHOWS a line of people trudging up a snow-covered footpath. A shot is heard; the first person in line falls. A voice-over says, "They are killing them like dogs." Another shot, and another body drops to the ground. A Chinese soldier fires his rifle again. Then a group of soldiers examines the bodies.
These images were captured in the Himalayas by a member of a mountaineering expedition who claims to have stumbled on the killing. The video first aired on Romanian television, but it only gained worldwide attention when it was posted on YouTube, the video-sharing website. (To view it, go to YouTube.com and type "Tibet, ProTV, China"). Human rights groups say the slain Tibetan refugees included monks, women and children. The Chinese government had claimed the soldiers shot in self-defense after they were attacked by 70 refugees, but the video seems to render that explanation absurd. The U.S. ambassador to China lodged a complaint.
Welcome to the "YouTube effect." It is the phenomenon whereby video clips, often produced by individuals acting on their own, are rapidly disseminated worldwide on websites such as YouTube and Google Video. YouTube has 34 million monthly visitors, and 65,000 new videos are posted every day. Most are frivolous, produced by and for the teenagers who make up the majority of the site's visitors. But some are serious. YouTube includes videos posted by terrorists, human rights groups and U.S. soldiers in Iraq. Some are clips of incidents that have political consequences or document important trends, such as global warming, illegal immigration and corruption. Some videos reveal truths. Others spread propaganda and outright lies.
Fifteen years ago, the world marveled at the "CNN effect" and believed that the unblinking eyes of TV cameras, beyond the reach of censors, would bring greater global accountability. These expectations were, to some degree, fulfilled. Since the early 1990s, electoral frauds have been exposed, democratic uprisings energized, famines contained and wars started or stopped thanks to the CNN effect. But the YouTube effect will be even more powerful. Although international news operations employ thousands of professional journalists, they will never be as omnipresent as millions of people carrying cellphones that can record video. Thanks to the ubiquity of video technology, the world was able to witness a shooting in a 19,000-foot-high mountain pass in Tibet.
This phenomenon is amplified by a double-echo chamber: One echo is produced when content first posted on the Web is re-aired by mainstream TV networks. The second echo occurs when television clips -- until now ephemeral -- gain a permanent presence through websites such as YouTube. Bloggers and activists everywhere are recognizing the power of citizen-produced and Web-distributed videos as the ultimate testimony. Witness.org arms individuals in conflict zones with video cameras so they can record and expose human rights abuses. Electoral watchdogs are taping elections. Even Al Qaeda created a special media production unit called Al Sahab ("The Cloud").
YouTube is a mixed blessing: It is now harder to know what to believe. How do we know that what we see in a video clip posted by a "citizen journalist" is not a manipulated montage? How do we know, for example, that the YouTube video of terrorized American soldiers crying and praying while under fire was filmed in Iraq and not staged somewhere else to manipulate public opinion? The more than 86,000 people who viewed it in the first 10 days of its posting will never know.
Governments are already feeling the heat of the YouTube effect -- and cracking down online. Almost a third of all reporters jailed this year were Internet journalists. The U.S. military recently ordered its soldiers to stop posting videos online. Iran's government restricts connection speeds to limit its people's access to video streaming.
But these measures have not stopped the proliferation of Web videos shot by U.S. soldiers in Iraq or kept savvy Iranians from viewing the images they want to see. And although Beijing has been effective in censoring the content its citizens can view, it has yet to figure out a way to prevent a growing number of videos of peasant rebellions from being posted online. In the long run, Web video censorship will fail because the same anonymity that makes videos difficult to authenticate also makes it harder to enforce governmental diktats.
The good news is that the YouTube effect is already creating a strong demand for reliable guides -- individuals, institutions and technologies -- that we can trust to help us sort facts from lies online. The millions of bloggers who are constantly watching, fact-checking and exposing mistakes are a powerful example of "the wisdom of crowds" being assisted by a technology that is as open and omnipresent as we are.