Can a negative tweet be considered an act of defamation?

If you complain to your friends about your landlord, you might be called an unhappy tenant. 

But if you complain to your friends about your landlord via Twitter, should you be called before a court of law? 

 In a case straight from the uncharted cyber-territory of social networking and personal responsibility, a Chicago renter is being sued by her former landlord for referring to her apartment as “moldy” in a message she sent to a friend. Because the renter transmitted the message using the micro-blogging service Twitter, her landlord accused her of “maliciously and wrongfully” defaming his company “throughout the world.” 

The bitter Twitter battle was on, but the court of law was quickly eclipsed by the court of public opinion. “Foolhardy,” was the verdict from a Harvard media law expert, who said the landlord was “inviting a PR nightmare.” 

The renter only had about 20 Twitter followers, so her tweet got no notice--until the landlord filed suit more than a month later. After a law blogger posted news of the court action, The Chicago Tribune picked up the blogger’s story, Twitter users spread it, Facebook, Digg, and StumbleUpon repeated it, TV and radio outlets followed, and by the end of one week, the tweet was heard ‘round the world in media reports in Russia, Australia, France, Italy, and Japan. 

“You guaranteed that way more than 20 people will hear about your moldy apartments,” was typical of reader responses during the story’s mega-media trajectory. 

The landlord—a property management company for 1,500 Chicago apartments—denied the mold allegation. Whether or not the landlord prevails in court, the case itself has raised numerous questions about personal responsibility and new media. “What is a tweet anyway?” asked the law blogger who originally broke the story. “Is it really considered publishing? Is it a conversation between friends in a public forum, like the electronic version of a coffeeshop, where you can gripe privately but have your gripes overheard? No one considers that defamation.” 

Tell us what you think: Should new media be held to old media standards? If you post a negative comment online—like a product review--should you be sued? In the case of the renter and the landlord, did either of them get it right?