The Shirley Sherrod story, which has dominated the news cycle of the past few days, shows what can happen when the media don’t follow that bit of wisdom.

A right-wing blogger, Andrew Breitbart, took a heavily edited videotape of Sherrod, a U.S. Agriculture Department field officer, addressing a NAACP gathering. The video contained language that suggested that Sherrod is a flaming racist and that the NAACP endorsed such bias.

The video ended up on the “fair and balanced” Fox News Channel, which then reported what the edited video showed about Sherrod. At that point, the stuff hit the fan.

Agriculture Secretary Tom Vilsack asked for Sherrod’s resignation, which she delivered. The White House endorsed Vilsack’s action, declaring that racism has no place anywhere in the federal government.

One big problem emerged right away: The video told only a fraction of the story. It turns out that Sherrod’s remarks were in fact a testimony to a remarkable journey she has taken in her life. It also turns out that Sherrod has many friends in rural Georgia, where she works, who have benefited from her help with issues that have arisen over many years.

And oh yes, many of those friends are white farmers and ranchers. Some of them rushed to her defense when the media began reporting the story.

This is a prime example of the Internet run amok. It also is an example of how so-called “advocacy journalism” needs some serious self-examination.

To his great credit, Vilsack apologized on live TV for acting prematurely. He didn’t offer that maddening passive-voice “mistakes were made” admission. He took personal responsibility for acting without knowing all the facts.

The cable network that reported the incomplete version of the story — the version that did all the damage to Sherrod’s reputation — has turned its fire on the White House and USDA for its hasty decision. It hasn’t yet apologized to Sherrod for fomenting the firestorm that erupted.

And the blogger? Well, he no longer needs to be treated as a serious purveyor of information. He’s a hack.

Sherrod says she considering a defamation lawsuit against Breitbart. Part of me hopes she goes for it. Another part of me wonders whether it’s worth it. Her reputation has been restored now that the edited video has been exposed for what it is: a hatchet job.