The Minnesota law that says defamation is a crime likely bit the dust last week, after the state Court of Appeals ruled it conflicted with that pesky principle called freedom of speech.

The case involved an Isanti County man who created sexually explicit Craigslist postings pretending to be his ex-girlfriend and her minor daughter, complete with their phone numbers. He was convicted of the gross misdemeanor of criminal defamation, which is defined as "anything which exposes a person or a group, class or association to hatred, contempt, ridicule, degradation or disgrace in society, or injury to business or occupation."

Lest anyone think that important free expression cases feature poets and political dissenters, they usually involve revolting speech, like angry men posting naked photos of ex-girlfriends online. In striking down the law, the appeals court felt compelled to pronounce the behavior in the case "reprehensible and defamatory." But the law criminalized even true statements, if they were delivered with malevolent intent.

While no one argued that the Isanti man was telling the truth, the appeals court ruled that he couldn't be prosecuted under such a blatantly unconstitutional statute.

About half of states have a criminal libel statute, although most are more narrowly written than Minnesota's, said Eugene Volokh, a professor of constitutional law at UCLA. Volokh filed an amicus brief in the case.

So how did Minnesota's criminal defamation law hang around for 52 years?

First, it wasn't used much. And when it was trotted out, the defendants didn't win much sympathy.

"Some of the speech was really, really horrible," speculated Chuck Samuelson, executive director of the American Civil Liberties Union of Minnesota. Prosecutors "felt they were doing their civic duty, that they were punishing people who did that."

Indeed, a review of recent criminal defamation cases is a journey through the filthiest gutter of human relations. Out of at least 70 charges filed since 1993, I could find records of only six convicted defamers who served jail time.

The most recent was last year, when a Rochester woman got 30 days in jail. Her offense: Posting on Craigslist that a woman was a child molester.

The longest term, the maximum year in jail, went to a Butterfield, Minn., man convicted of criminal defamation in 2009. In 2012, a Burnsville man got 20 days in jail after he drunkenly wrote a Craigslist post that resulted in a sex-seeking stranger knocking on his former girlfriend's door. A St. Paul man spent two days in jail in 2013 after he posted nude photos of his ex-girlfriend on Flickr, after he said she cheated on him.

A 2013 arrest warrant is outstanding for a man who sent 117 text messages, including some intimate images of his ex, to one of her co-workers.

In the past, many notable defamation cases involved dirty tricks during campaigns and threats against law enforcement, but now it seems to be all about retaliation, specifically "revenge porn."

"It is rampant," said Rebekah Moses, public policy manager for the Minnesota Coalition for Battered Women. Batterers and perpetrators of sexual violence are increasingly using photos, videos and Internet postings, and "if they lose power and control, they use it as a tool of revenge," Moses said.

Minnesota lawmakers are considering bills that target this kind of abuse. A House bill introduced last session would have made it a felony to disclose sexual images of a person unless the person consents to the disclosure.

It's a much narrower restriction than the criminal defamation law, but one that could run into the same constitutional trouble. Samuelson said he doesn't see a need for any criminal penalty for defamation, given that people can take out restraining orders or lawsuits.

With its scope upheld by the U.S. Supreme Court for decades, the First Amendment encompasses the spectrum of human expression, from criticism of the president to the online rants of a jilted boyfriend.

Contact James Eli Shiffer at james.shiffer@startribune.com or 612-673-4116.