Online sleuths keep trying to solve true crimes. The Baby Reindeer obsession is just the latest

Chances are you've heard of Baby Reindeer, even if you haven't watched it yet.

Netflix's dark and buzzy series spent four weeks as the most popular show on the streaming service globally, and it was also the top show in Canada. The mini-series by Scottish comedian Richard Gadd centres on the main character's harrowing experience of being relentlessly stalked by a woman, which Gadd says is based on his own life.

But the show is making headlines not just for its popularity but for the wave of online detectives trying to identify some of the more unsettling characters it portrays, including Martha, the stalker. Now the supposed real-life "Martha" says she plans to sue, and Gadd has pleaded with fans to stop the sleuthing.

As people dig into the history and personal life of the Scottish lawyer allegedly the inspiration for the Martha character in the show, some experts point out that this is exactly the kind of response we should come to expect given society's obsession with true crime.

People have been armchair sleuths since the first season of the hit podcast Serial aired 10 years ago, and it's one of the reasons the series became such a phenomenon, crime writer and true-crime critic Sarah Weinman told CBC News from New York City.

On the one hand, the idea that you can participate allows people to contend with their frustration or sense of helplessness about the criminal justice system, said Weinman, author of Scoundrel and The Real Lolita.

And true crime provides a sense of community where people — largely women — can bond over their obsession with it, she said.

"The problem is that participatory element kind of puts you in a position that violates a lot of boundaries," Weinman said.

What we're seeing with Baby Reindeer is the blowback to this kind of immersive, interactive product, where people can watch or listen to true-crime content, then engage further, said Michael Arntfield, a criminologist and author at Western University in London, Ont., who's also a former police officer.

"People take on a pseudo-investigative role themselves, looking into tracking these people, looking for alternate theories to the cases, opening up discussion forums or starting their own podcasts to carry on where these other products left off," he said.

In the case of Baby Reindeer, Gadd tried to conceal the identity of the woman who he said had stalked him. It didn't work.

The series begins as the character of Martha (played by Jessica Gunning) walks into a pub where Donny (played by Gadd) buys her a tea, sparking a "suffocating obsession that threatens to wreck both their lives," according to the Netflix series description.

Martha is described as mentally ill and vulnerable, and she leaves Donny "hundreds of hours of voice messages and north of 40,000 emails." Gadd told GQ he's never revealed the name of his real-life stalker to the media and that he changed some key facts about her for the show.

Gadd said he "went to such great lengths" to disguise the real woman's true identity that he doubted she would recognize herself. Later, according to Forbes, Gadd pleaded in a now-expired Instagram story for people not to "speculate on who any of the real life people could be. That's not the point of our show."