Sane and rational people wonder how a group of teenagers could beat a cheerleader, videotape the incident and make jokes about it in jail afterward. Sane and rational people also wonder how the videotape could go online — with an ad at the beginning of it.

Media people often fret about sites such as Craig’s List, YouTube and MySpace. They are seen as competitors for readers’ time and advertisers’ money. But what they make up in quantity — in the form of huge audiences — they lose in credibility.

They lose that credibility because they do not have any control over the content that gets posted by their users. They can only take it down after the fact.

The lack of trust and credibility translates into the lack of quality, support by site visitors who matter and also support by advertisers who matter. In the long run, the chaos and disgust they create will erode their brands into failure.

Media sites have an opportunity to declare how they are different and better than sites without ethics by committing to an online ethical policy that mimics what they do in broadcasts and publications. A privacy policy is a must for any credible site; an ethical policy will only enhance that credibility.

Fairness, accuracy, objectivity and other ethical standards aren’t old-fashioned notions that will drift away. They have a moral purpose and a business purpose. They will help ensure the survival of quality media operations.

Readers and advertisers can take only so much trash.