The abduction and extraordinary rescue of Cleo Smith in Western Australia has played out as a dramatic and ultimately heart-warming story of dogged police work and a little girl returned to her family. For hundreds of thousands of social media users, however, her disappearance became a kind of true-crime whodunnit in which they could play detective in real time.

Earlier this year, the case of 22-year-old American woman Gabby Petito went viral on social media ^[1]. Her disappearance, the discovery of her body, the vanishing of her fiancé, Brian Laundrie, and the finding of his remains were picked up, pored over, repackaged and consumed as entertainment by millions of social media users across multiple channels.

On TikTok, mediums and tarot readers declared that they could sense not only that Petito was dead (before her body was found) but how she was murdered. On YouTube, content creators made daily video updates about the case, and on Facebook, groups with tens of thousands of members, and in some cases hundreds of thousands, speculated and exchanged theories about what happened and who was responsible. Books about Petito are already available on Amazon and Etsy, people are selling ‘Gabby Petito’-branded merchandise and even items accusing the Laundrie family of being involved in Petito’s murder. Petito was a small-scale aspiring Instagram influencer during her life, but her account gained over 1.2 million new followers after her death.

While the attention on Cleo Smith’s case had not reached the fever-pitch surrounding Petito, the same dynamics were emerging. Multiple Facebook groups dedicated to the four-year-old were set up, one with over 60,000 members by the time she was found. On Twitter, harassment campaigns were launched against Cleo’s parents by accounts asserting that the couple had murdered their daughter and alleging that they were engaged in other crimes as well. A TikTok tarot reader declared that Cleo was dead, just like in Petito’s case.

In some instances, the same people were spreading this misinformation. As fewer developments occurred in the Petito case, the social media machine looked for new fuel. Posts about Cleo were shared into Petito Facebook groups, and influencers who’d built a following talking about Petito incorporated updates on the Smith case.

Many ^[2] have linked ^[3] these online subcultures ^[4]’ treatment of real crimes as a kind of hobby ^[5] with the rise in popularity of the true-crime entertainment genre ^[6], in which audiences are taken through the gory details of real crimes and often encouraged to see themselves as detectives. But Petito’s case was an ongoing investigation, not a polished Netflix docuseries.

Intense, prurient interest in criminal cases isn’t new, but the role of social media platforms adds new and powerful dynamics.

Once, a disappearance or a death might have interested only a local or national audience, but social media has erased any boundaries on who can engage with a case. A significant number of those creating content about Cleo were American. The people at the centre of a case—investigators, families, witnesses and anyone who may fall under suspicion—are put under an intense spotlight.

Algorithms help social media companies curate and amplify information to can keep users on their platforms by feeding them content they’re likely to engage with. When, as an experiment, I followed one of the largest Gabby Petito Facebook pages, Facebook instantly recommended that I follow several other Petito pages, the page for ‘Dog the Bounty Hunter’ ^[7], pages for several other missing women and a page for true-crime enthusiasts. The platform actively encourages users to fall deeper and deeper into such content.

Social media platforms use algorithms to heighten a conversation’s intensity by amplifying the most engaging content—often the most extreme or incendiary. We’ve seen the impact that can have on conspiracy theory movements like QAnon, which (while it has many contributing factors) has been powerfully shaped by algorithmic amplification. When you take that dynamic and apply it to an ongoing criminal investigation, it’s likely that the most extreme theories about how the crime may have been committed and who may have been responsible will gain traction.

Beyond the mechanics of the social media platforms are social dynamics within the ‘communities’ these processes have created. Many ^[8] social media influencers ^[9] built a following around their Gabby Petito content. Feeding that audience meant creating more content and competing with rivals to put forward the most engaging theories and information and speculation about Petito’s death. That got harder as Petito updates dried up, which probably drove some to pivot towards Cleo Smith and missing Californian woman Heidi Planck.

Once social media communities have enough people invested in keeping them going, they develop their own momentum. That appears to be happening in the community which started with the Petito case.

While not every investigation will receive such attention, where it does happen it’s likely to affect how police, welfare bodies and other parties approach the case.

Global harassment and abuse may create a need for additional support for family members or witnesses subjected to vicious speculation, as were the parents of Cleo Smith. The intense harassment and abuse of Brian Laundrie’s family included protesters camping outside their home ^[10] and a woman with a bullhorn ^[11] shouting at them during the search and after the discovery of his body. The parents said ^[12] they wouldn’t have a funeral for their son, and police pleaded with the protesters to go home and leave the family to grieve in peace for at least one night. That underscores the threat to the mental health, wellbeing and reputation of anyone linked to the case.

Along with mental health support, families may need practical assistance to adjust privacy settings on social media and lock down their digital footprints. Police officers may also become targets.

Managing the sheer volume of public tip-offs and sifting through them to find potentially useful information is likely to be challenging for investigators. Another impact may occur when police are narrowing in on a suspect but don’t wish to alert the person that they’re under investigation. If the target’s name starts to trend on social media, or if sensitive information is published about investigators’ activities and movements, that could alert the suspect to destroy evidence or change behaviour.

Then there’s the role of social media platforms. While speculation about criminal cases and disappearances is well within the bounds of free speech, it’s reasonable to consider whether platforms should prevent their algorithms from driving users down ghoulish rabbit holes or amplifying poorly founded speculation about whether an individual may be a murderer to millions of people around the world. It’s worth considering whether measures applied in other contexts, such as preventing relevant hashtags (or people’s names) from trending, and turning off recommendations for related groups and pages, should be implemented here.

At the heart of this phenomenon are real human tragedies. The transmutation of the suffering of people like the Smith and Petito families into social media content for the dissection of true-crime hobbyists raises a range of practical questions, but it should also spark a deeper ethical conversation about the consumption of tragedy as entertainment.