From Seattle Post Intelligence:
PERUGIA --Italian authorities have served the parents of Amanda Knox with legal papers notifying them they are under investigation for defamation, an accusation related to their allegations that police brutalized their daughter.
People might feel sympathy for Amanda because she's young and cute (despite the denim jacket). The Italian people already distrust their police. Heck, we aren't very big fans of our own police, here in Washington. These claims, truth or not, only reinforce a pre-existing distrust of police.
What actions do the police, as employees of the state, have against these allegations. By rules of logic, they are unable to prove that misconduct did not occur. Their best option is to maintain their professionalism and transparency throughout the case.
Cases of defamation of character in American courts are typically awarded to situations regarding individuals and private organizations. Cases that hold up in court are typically follow a utilitarian argument, gauging the malicious repercussions of the message against the social utility of the content.
For example, a department store may not post photographs of shoplifters on its front doors because it is of no use to the public to see the faces of people who have already paid for their crimes. Also, the information may hurt business opportunities otherwise available to publicly shamed individuals. A libertarian argument would suggest that public image is like a commodity that holds value. Damage inflicted upon public image is like damage of any other property and must be compensated for.
People exempt from pressing defamation charges are public figures such as politicians and celebrities. Their public image is regarded as public property and a fair subject for free speech.