“Check the source” may be the first rule of journalism. But in the coverage of the protests in Iran this month, some news organizations have adopted a different stance: publish first, ask questions later. If you still don’t know the answer, ask your readers.

CNN showed scores of videos submitted by Iranians, most of them presumably from protesters who took to the streets to oppose Mahmoud Ahmadinejad’s re-election on June 12. The Web sites of The New York Times, The Huffington Post, The Guardian newspaper in London and others published minute-by-minute blogs with a mix of unverified videos, anonymous Twitter messages and traditional accounts from Tehran.

The blogs tend to run on a separate track with more traditional reporting from the news organizations, intersecting when user videos and information can be confirmed. The combination amounts to the biggest embrace yet of a collaborative new style of news gathering  one that combines the contributions of ordinary citizens with the reports and analysis of journalists.

Many mainstream media sources, which have in the past been critical of the undifferentiated sources of information on the Web, had little choice but to throw open their doors in this case. As the protests against Mr. Ahmadinejad grew, the government sharply curtailed the foreign press. As visas expired, many journalists packed up, and the ones who stayed were barred from reporting on the streets.