MILAN (AP) — Italy’s highest court this week takes up the Amanda Knox case for the second time as a parallel trial-by-social media rages online, with partisans on both sides seeking to shape public opinion over a murder case that has polarized observers in three nations.

While the Internet advocacy and sparring over the Knox trial details — on blogs, forums and most vociferously on Twitter — have no bearing on the real court case, observers and participants say it does have a role in shaping public opinion, particularly in the United States, where the exchanges are most acerbic.

And public opinion could eventually have some bearing, if a confirmed guilty verdict requires Knox to serve a sentence and Italy seeks to extradite her.

“This has become their life, and both sides are desperate to win any way they can. Even if that is in the court of public opinion, they will take that win,” said Laurie Levenson, a law professor who directs the center for legal advocacy at Loyola Law School. “Everyone has woken up and realized that the law is not etched in stone. It is in the eye of the beholder and they are trying to influence that.”

The Italian Court of Cassation on Wednesday is expected to rule on Knox’s and her former Italian boyfriend Raffaele Sollecito’s appeal to their guilty verdicts in British student Meredith Kercher’s 2007 killing, issued last year by a Florence appeals court that sentenced Knox to 28 ½ years and Sollecito to 25 years.

Both had been found guilty by a trial court in Perugia, then freed after a Perugia appellate court overturned the convictions, only to find themselves back in an appellate court after the high court vacated the acquittals in a harsh rebuke of the Perugia chief appellate judge’s reasoning.

Knox, who spent four years in jail during the investigation and after her lower court conviction, remains free in the United States. She has vowed never to return willingly to Italy. If her conviction is upheld now or in future decisions, any decision on her extradition will include a political component that could, in some part, be swayed by public opinion.

“She would need a groundswell of support to at least stave off the (U.S.) government from moving forward” on any extradition request from Italy, said Levenson.

Eugene McLaughlin, a professor of criminology at the City of University London who is studying the early days of British media coverage, calls the case one of the first examples of “trial by social media,” one that put the photogenic U.S. defendant at the center of attention, eclipsing the victim in most accounts.

“The case is almost beyond legal adjudication,” McLaughlin said. “No matter if Amanda Knox or Raffaele Sollecito are found guilty or not guilty, it has taken on an after-life of its own.’

The protracted online battle took root in the Paleolithic era of social media, when tabloids plumbed Knox’s MySpace page for early photos of a smiling and carefree student, wisps of hair blowing from beneath a rolled knit cap, picking up on the “Foxy Knoxy” moniker.

To the British tabloids, the University of Washington student was a she-wolf bent on seduction. The image they portrayed of a deceptively wholesome American roommate with a taste for adventure took hold in the public imagination after the young lovers were filmed embracing outside the crime scene and shopping for lingerie days after the murder.

McLaughlin said Knox was assumed guilty in the British press in the early days of coverage, an impression that solidified when Italian police leaked that she had confessed — a confession she later said was forced.

“Certainly in the British media, among key newspapers, she was guilty way before they got near any sort of court,” McLaughlin said.

In the United States, the story was different. Knox’s parents were frequent guests on U.S. TV networks and Knox’s image was closely managed by family spokesman David Marriott’s PR firm. The company set about disputing what it saw as misconceptions about Knox spawned in the British tabloids and the Italian media in the months after her arrest — a task that eventually landed Knox a reported $4 million book deal.

Sollecito, for his part, has responded to requests to speak with non-Italian traditional news outlets that he will grant interviews only in exchange for money.

It was in this PR breach the social media engagement ramped up, with blogs, discussion groups, wiki sites and Twitter exchanges on complex Italian court opinions and expert testimony on DNA evidence.

One of the latest hashtag battles is being waged by Knox supporters against Sollecito, seeking a boycott of donations to his legal defense fund until he clarifies whether his high court defense strategy amounts to a sellout of Knox. But over the months and years, the hashtag battles have also fought over minute details of the DNA evidence and tussled over highly technical forensic documents, which McLaughlin said can be open to multiple interpretations.

This trial-by-social media— conducted in English and unburdened by the weight of law — is being carried out by largely by trial watchers with no direct connection to either the victim or the defendants.

“It was like a big whodunit, and I like puzzles,” said Edward McCall, the online alias of the founder of the Murder of Meredith Kercher wiki, one of among a dozen mostly U.S.-based sites on both sides actively monitoring the case. McCall, who says the site is close to achieving its goal of posting translations of all court documents and transcripts, asked not to use his real name to protect himself and family members from harassment.

McCall said he was motivated by a desire to confront the pro-Knox PR he felt was prevalent in the U.S. discussion, and that he was now seeing language from his articles seeping into the discussion.

As well-meaning as the sites are, the Kercher family lawyer, Francesco Maresca, said translating complex court documents for an English-speaking audience had little value for readers who don’t know have the Italian law knowledge to interpret them properly.

“These trials are very difficult. It is not that everyone can play lawyer. If your knowledge is average, these are very technical questions,” Maresca said. “And after that, it slides into gossip.”