Though YouTube has long been ineffective at regulating content, the video platform is now under serious scrutiny after it’s been discovered that there is a network of pedophiles openly operating on it.

Clips of children exposing their underwear, genitals, and buttocks are racking up millions of views — and to make matters worse, YouTube is monetizing the sick videos with ads from big brands like L’Oreal, Maybelline, Grammarly, Fortnite, Disney and McDonald’s.

While many of the videos are meant to innocently portray children doing yoga, swimming, and playing games like Twister, pedophiles are sharing timestamps that reveal shots where exposed nipples and genitals can be seen. Most of the videos feature girls, with some of them appearing as young as 5 years old.

Clips of these little girls performing gymnastics, doing cartwheels, and eating popsicles are being commented on by thousands of semi-anonymous users who are sharing time codes for inappropriate shots as well as links directing people to similar videos. Many are even exchanging their phone numbers and making promises to share more videos on Kik or WhatsApp.

In some cases, the comments of confused kids who naively uploaded the videos are getting caught up in the mix with those of the pedophiles. On one video of a girl and her friend doing yoga, the child asks a commenter why the video made him “grow.” The clip has accumulated two million views and features a L’Oreal pre-roll ad.

Many of the comments tell the girls how “beautiful” and “pretty” they are, and others are simply too disturbing to repeat. They also often ask for other videos with different clothes or better lighting. Disturbingly, these YouTube users commonly feature their own collections of videos exploiting children that have been scraped from YouTube.

Several advertisers who have found out the types of content their ads are accompanying have pulled their ads or expressed serious concerns to YouTube about the matter.

“We’re absolutely horrified and have reached out to YouTube to rectify this immediately,” said a Grammarly representative. “We have a strict policy against advertising alongside harmful or offensive content. We would never knowingly associate ourselves with channels like this.”

In the meantime, Fornite has put all of their pre-roll ads on hold. “Through our advertising agency, we have reached out to YouTube to determine actions they’ll take to eliminate this type of content from their service,” said a spokesperson for the company.

“[We find it] repulsive that pedophiles are using YouTube for their criminal activities,” added a rep for the World Business Forum.