After taking a “daggy dad” photo of himself with a cardboard Darth Vader last year, a Melbourne man found himself labelled a sexual predator on social media. A woman who believed he was photographing children posted his image online, and the accusations were shared more than 20,000 times, exposing him to a torrent of harassment and abuse. Only by handing himself in to police was he able to clear his name. While the truth was eventually made clear, the damage was already done. His reputation was obliterated, sacrificed by virtue of a social media trial.

In our attempts to champion justice against violent and abusive criminals, a new injustice is emerging. Pillorying and prejudgment of the accused is rife on social media; threats and calls to violence are not uncommon. Allegations alone are justification for naming and shaming, leaving innocent people at the mercy of outraged hordes. Our fundamental rights are being ignored in the fervent march towards a better society, leaving the idea of justice a broken, battered shell in its wake.

“You don’t have a presumption of innocence in a trial by media, but you do in a court,” said Tim Vines, vice-president of Civil Liberties Australia. “But if you have a trial by media, you can’t have a legal trial. You’ve already muddied the waters and made it impossible for the person to put forward their case.”

Trial by media has always existed in one form or another, but the legal system was able to maintain a level of control over information released in traditional media. But where public opinion was filtered by third parties like editors or limited to local communities, the internet has removed these filters. Social media has given everyone a voice, but while everyone has the right to hold an informed opinion, publishing them has a direct impact on the judicial system. Our rights are not only legal terms but part of our social contract, Vines says, and ignoring them can harm more than the accused.

“People who say ‘I’m entitled to post whatever I want online because I’m not bound by presumption of innocence’, well, that’s technically true. But in doing so you possibly remove the only form or legal mechanism society has to denounce this person’s conduct and actually punish them.”

It’s a fear that prosecutors, police and family raised during the Jill Meagher murder trial, a plea that has fallen on deaf ears; similar concerns are swirling around the trials of the alleged killers of Sarah Paino and Cole Miller. Being charged, after all, is not the same as being guilty, and history is littered the corpses of the wrongly accused.

The accused in the 2006 Duke lacrosse rape scandal — who, before being declared innocent by authorities, were harassed by protesters brandishing signs emblazoned with “CASTRATE!” and “TIME TO CONFESS!” and had their images plastered on “Wanted” posters across the school — still feel the aftershocks today. After the Boston Marathon bombing, the family of missing student Sunil Tripathi were hounded by online harassment, threats and terrorism accusations after he was wrongly identified as a suspect by online sleuths. But rather than seeking protection against the harms wrong or false accusations can inflict, social media users are instead kicking the door wide open for them.

Innumerable community awareness groups dedicated to naming and shaming have sprouted online. And while the majority of allegations might be statistically true, as advocates claim, convicting on nothing more than the statistical likelihood a crime was committed ignores a simple truth about humanity: we’re fallible. Sometimes we misremember. Sometimes we lie. Yet, with more than 2 billion people connected to the internet globally, the potential harm from malicious accusations is staggering. While some social media sites do attempt to mediate or delete offending content, according to Professor Mark Pearson, journalism and media law expert at Griffith University, it can still be an exercise in futility.

“They [forums] are of such a magnitude in speed and number of communications, there is no practical way they could intervene to stop a message that someone could be sending which could be offensive or even illegal for someone else,” Pearson said.

Anonymity is a distant memory; pulling up stakes and starting afresh in a new village is impossible in a global community. Employers check our backgrounds online. Potential partners can turn over any stone they wish, and the digital records of our lives are permanent. While suing for defamation is an option and social media posts are subject to defamation laws, Pearson says the nature of the online environment presents unique and potentially insurmountable problems.

Tim Vines agrees, pointing out the existence of defamation laws shouldn’t be used as an acceptable excuse to justify public shaming.

“Defamation is an expensive process to go through, and it may only be effective against the initial publisher … It’s going to be very hard if that comment has been picked up and then reposted elsewhere,” he said.

It’s a problem compounded by the viral nature of hashtag justice, seized upon and spread in the heat of outrage and passion. As horror fans know, once the genie is loose it can be impossible to shove back in.

In December, adult film star James Deen was the subject of rape and assault allegations made online by his ex-partner Stoya and several co-workers. The #solidaritywithstoya hashtag swept through the internet; Deen’s regular column with The Frisky was cancelled, and production companies dropped him. Having never been charged, Deen remains in limbo. Advocates against sexual assault believe this social punishment is fair for such an abuser, but his innocence remains a distinct and untested possibility. It’s a risk any accusation without charge carries, but while public figures like Deen might possess the resources to rebound, that’s a luxury the average person doesn’t have.

While our judicial system still has room to improve, discarding it for trial by social media is not a step forward. It destroys our ability to hold the guilty to account. It exposes the innocent to unfair or malicious vilification. It positions the online community as judge, jury and executioner. Our human rights were designed to prevent these from happening; but when it comes to social media, rather than meeting these breaches with contempt and condemnation, we’re embracing them instead.