Washington (AFP) - The Supreme Court took on a sticky social media issue not envisioned by the drafters of the US Constitution Wednesday: are an online stalker's messages that the recipient considers menacing protected by fundamental free speech rights?

In a two-hour discussion that dropped references to intimidating lyrics by Eminem and burning crosses to threaten Black people, the justices were asked to decide whether Billy Counterman was correctly jailed in Colorado for the thousands of unwelcome Facebook messages he sent to country singer Coles Whalen over 2014-2016.

To Whalen, Counterman's messaging, which persisted even when she blocked him and started new online accounts, left her in a constant state of fear. 

He wrote to her messages such as "die, don't need you", and "staying in cyber life is going to kill you," and indicated that he had physically followed her.

The cumulative impact left her frozen and unable to perform after doing hundreds of shows a year and releasing six albums, she said.

"I was terrified that I was being followed and could be hurt at any moment; I had no choice but to step back from my dream, a music career that I had worked very hard to build," she said ahead of the hearing.

In 2016 she filed a complaint in Colorado courts after learning that Counterman had previously been jailed for threatening to injure several other women.

The next year he was found guilty by a jury and sentenced to four and a half years in prison.

Limits to free speech

That conviction has sparked a case that has libertarians, activists on the right and left, and media siding with Counterman in his suit against Colorado.

Free speech advocates worry upholding his conviction could chill free speech by opening the door to the prosecution of anyone whose speech is perceived as threatening by another person, without proof of intent.

Colorado state laws don't require an assessment of the speaker's mental state, and so Counterman was convicted without a determination of his intent.

That, his attorneys said in their petition to the Supreme Court, violates his free speech rights.

They said he did not intend to threaten Whalen, that he suffers from "mental illness," and that Whalen perceived threats that were not real.

"Criminalizing misunderstanding is especially dangerous in an age when so much communication occurs on social media," Counterman's attorney John Elwood told the high court Wednesday.

The standard for a conviction, he said, is that the person speaking, or messaging, "knew that the words would cause fear."

Enabling stalkers?

Colorado Attorney General Phil Weiser told the court that such a standard would enable abuse of free speech rights.

"Requiring specific intent in cases of threatening stalkers would immunize stalkers who are untethered from reality. It would also allow devious stalkers to escape accountability by insisting they meant nothing by their harmful statements," he said.

"Ninety percent of actual or attempted domestic violence murder cases begin with stalking," he noted.

Even if some of Counterman's messages seemed benign, he said, the threat came in the context and cumulative effect -- making them different from joking threats between friends or family members. 

But justices queried whether the perception of a threat by the person on the receiving end was enough to deny someone's free speech rights.

"We live in a world in which people are sensitive, and maybe increasingly sensitive," said Justice Neil Gorsuch, making reference to trigger warnings announced before university lectures to avoid disturbing some students.

Weiser said that the standard for what constitutes a real threat is not determined by "eggshell defendants" who are so fragile as to perceive threats everywhere.

Several justices still showed concern that endorsing Colorado's conviction of Counterman would amount to setting new limits on free speech.

The court should decide the case by the end of June.