A viral YouTube video is exposing what appears to be a worldwide ring of child exploitation videos hidden in plain sight on the site and aided by its algorithm to share questionable content featuring adolescent girls — videos complete with advertising from major companies.

The video was compiled by a YouTuber named MattsWhatItIs, showing how the algorithm meant to recommend similar videos for a YouTube account can actually be triggered to share nothing but this questionable content. The user created a new account — one where the algorithm had not yet been set — and made a few clicks starting with a normal search to find videos uploaded by a preteen girl. Though this video was innocent in nature, likely uploaded by the child in question, it caused the site to offer nothing but videos of other young girls in the sidebar.

As the video explored deeper into these suggested videos, it showed what appeared to be a ring of child exploitation being carried out in the open. Users posted timestamps of points in the video where the children were in compromising positions, made inappropriate comments, and reportedly even shared links to child pornography. Commenting had been disabled on some of the videos, showing that YouTube appeared to be aware of the inappropriate comments but did not take down the actual videos.

Some of the users even interacted with the children who made the videos, encouraging them to create “challenge videos” that placed them in further compromising positions. These comments came from across the world, including many from Eastern European countries and Asia, the video showed.

Many of these videos had advertising from major companies, including Google Chromebook, GNC, and even Walt Disney World.

As the video captured viral attention — shooting to the top of Reddit and trending across social media — many people called on YouTube to stop the practice. Others called out the site for allowing the clearly exploitative videos to be monetized with advertising. On Twitter, the hashtag #YouTubeWakeUp trended, with many sharing links to the video documenting the practice and tagging the companies that had advertising in the videos.

I'm absolutely DISGUSTED at YouTube for ignoring the sexual exploitation of minors on it's platform!!! Watch this video for proof that its algorithm facilitates pedophilia#YOUTUBEWAKEUPhttps://t.co/Jkwjppvu23 — Amanda Weisbrod (@amanda_weisbrod) February 18, 2019

Just found out about #youtubewakeup

I'm truly disgusted. @YouTube fix your priorities — Will (@thisbtfo) February 18, 2019

YouTube has already taken measures to curb child exploitation across its platform, leading CEO Susan Wojcicki to announce in 2017 that the company has increased its number of human moderators by more than 10,000 in 2018.

BuzzFeed News sent YouTube dozens of such videos — some with millions of views — showing children in predatory situations https://t.co/7mFNJ0SA95 — BuzzFeed News (@BuzzFeedNews) November 22, 2017

As Buzzfeed News noted, Wojcicki said that the site would be “carefully considering which channels and videos are eligible for advertising” and applying stricter criteria. But as the new viral video documenting child exploitation on the platform shows, the process doesn’t appear to be working.