YouTube “challenges” have always been central to the social platform's internal culture: whether it's vloggers slapping 100 layers of make-up on their face, or forcing themselves to eat a series of repellent food items.

It's difficult to spend any significant amount of time on the site without stumbling into a challenge in some form or another, yet filmmaker David Farrier has uncovered something far more sinister at work in YouTube’s shadowy recesses – turning the “challenge” trend into a tool for exploitation.

Farrier is New Zealand’s leading entertainment reporter, although he has gained significant acclaim over the course of this year thanks to his sensational documentary Tickled; an exploration of exactly what can be found hiding within the most innocuous corners of the internet.

When a friend linked him to a video of “competitive endurance tickling” – young men strapped down and tickled into oblivion by other young men – it all seemed destined to be another passing quirk. That is until Farrier’s investigations soon uncovered the real motivations behind the source of these videos, the mysterious Jane O’Brien Media.

What followed was an astonishing tale of exploitation, power, and deceit; ideas that he’s seen resurface as part of his next investigation, penned for New Zealand's The Spinoff, which looks into YouTube's “Shrunken Ally and Maddie Challenge” trend. Young YouTubers are filming themselves responding to a questionnaire supposedly sent out by a pair of teenagers called Ally and Maddie, who claim they were “watching the movie Honey We Shrunk Ourselves and after we were done watching it we got on the topic of what we’d do if the people we hated were shrunk to that size!”

What follows is a series of 15 questions all connected to the idea of being very small: this may seem innocuous, but Farrier's work has uncovered these videos are in fact being used as fetish content for adults. They're connected to the microphilia fetish, which involves fantasies of being shrunken down to minute sizes.

The fetish normally focuses only on adults; it's a self-regulating community that usually ensures only those above the age of consent are involved in any form of content, which is why Farrier was alerted to the videos by a member of the microphilia community who was very concerned about the proliferation of the Ally and Maddie videos on YouTube.

Tickled - trailer

The issue here is that these videos don't appear to legally come under the category of grooming and show no obvious breach of the law; yet, these specific challenges seem to form only part of what's a wider trend of minors being unwittingly exploited for fetish content, with other similar challenges named “The Bug Challenge” and “The Lego Challenge”.

Online safety organisation NetSafe has stated parents have a responsibility in monitoring any Q&As their children may take part in on YouTube: “Parents should be across it. Children are often more technically savvy, but they’re not emotionally or mentally mature enough to deal with some online situations.”

When contacted by Farrier, Google's head of communications and public affairs for the Asia-Pacific region, Gustaf Brusewitz, responded: “There are more than 400 hours of content uploaded to YouTube every minute and we do not comment on individual videos. We take safety on YouTube very seriously and our community guidelines clearly state that inappropriate material is not allowed on our site. We remove violating videos when flagged by our users and disable the accounts of repeat offenders.”

“YouTube has a zero-tolerance policy for sexual content involving minors. Uploading, commenting, or engaging in any type of activity that sexualizes minors will immediately result in an account termination.”

Brusewitz added: “We work closely with organisations such as charities, others in our industry and government bodies dedicated to protecting young people. YouTube has a variety of educational materials and tools such as Safety Mode which parents can turn on to stop age-restricted and inappropriate videos from coming up.”

The Independent has also reached out to YouTube for comment.