My Sunday column about Carol Canniff's purchase of a used minivan with a broken odometer unleashed a spirited discussion with more than 150 comments. People tend to have strong opinions about the purchase of transportation, and that predates the automobile - see Mark Twain's horse buying remorse upon learning that his "genuine Mexican plug" that turned out to be a wildly bucking monster.

One commenter on my story describe the others as "rabble." But one of the things I find truly revolutionary about online news is the ability of the parties in the story to speak directly to readers. A representative of the dealership added a rebuttal and critique of the story, and readers then responded to that post. Then Canniff's brother, who was quoted in the story, added his own critique. While news organizations are consumed with the challenges posed by online commenting, it's now hard to imagine journalism before readers could publicly register their disgust or delight or bewilderment.