TikTok is home to many NSFW trends (see: the ubiquitous WAP dance), many of which are fun and sometimes empowering. Yet some of these fads have been embraced by the younger segments of TikTok’s user base, prompting concern among some members of the community, particularly considering that TikTok videos frequently end up on platforms like Pornhub and Reddit.

One new trend features creators arching their backs and pantomiming various sex acts to a snippet of “Goodbye” by Feder feat. Lyse. Some of the videos have millions of views; one such video, featuring a minor who is listed on her bio as 17, had more than 5.7 million likes before it was removed by TikTok after an inquiry from Rolling Stone. Many of the creators toward the top of the page for the audio appeared to be underage. (TikTok has since removed many of them.)

A number of these videos have been cross-posted to subreddits devoted to cataloguing attractive women on the platform (despite rules ostensibly preventing users from posting content featuring minors), some of which have hundreds of thousands of subscribers. Compilations of the videos featuring some underage creators have also been posted to YouTube. (YouTube did not respond to requests for comment.)

The popularity of the trend among underage creators has sparked concern with members of the TikTok community, who are worried about minors being exploited on other platforms. “Can minors stop doing this trend? Y’all are gonna end up on some Cp [child porn] site,” one TikToker, @bobahoar, says in a video. Another TikToker, @bloodbathbey0nd, says in a video, “I will talk anybody under the table about female empowerment and young women doing whatever they want with their bodies, but where I’m drawing the line is young children do not understand the consequences of posting these videos.”

The trend sparked further controversy after a popular TikToker, @urgirladrie, made a video that got more than 464,000 views, warning younger followers that a compilation of the trend had ended up on Pornhub. She tells Rolling Stone that she was initially wary of speaking out against younger users participating in the trend. “It seemed these girls were getting hate from the incels for feeling themselves and it just felt wrong to approach a minor as a 23-year-old and say, ‘You’re being sexual, stop, people are going to get off to this,’” she says. She changed her mind, she says, when she found a video compilation on Pornhub. “It disgusted me so much,” she tells Rolling Stone. “This is vile and wrong. I made a video immediately to warn these girls to private [their TikTok videos] or at least be aware.” She says she and her followers reported the video, prompting Pornhub to take it down.

Though the fact that the video ended up on Pornhub could not be independently verified by Rolling Stone, we found other examples of TikTok content featuring very young creators being posted on the platform, including a video of a young-looking woman participating in the trend, a dance compilation, and a “WAP” compilation, both of which featured at least one confirmed underage TikToker, according to the ages in the creators’ TikTok and Instagram bios.

It is not uncommon for TikTokers, whether they’re of age or not, to end up on Pornhub. A quick search yielded more than a dozen compilations and individual videos of clothed female TikTokers doing SFW dances with titles such as “CRAZY THICK White Girl Does WAP Dance” and “A New TikTok Slut Is Born.” Often, the creators’ handles are visible in the uploaded videos; sometimes, their SFW videos are featured in a collage next to nude or sexually explicit content, or spliced with moaning sounds. It is unclear whether the creators in the videos are aware their videos have been uploaded to Pornhub.

Pornhub has previously faced criticism for hosting nonconsensual content, despite claiming to use patented technology to remove “unauthorized” videos. In April, BuzzFeed News also reported that a slideshow of a popular TikTok creator’s nudes, taken when she was underage, was posted on the platform, causing her name to trend.

In an email, Pornhub denied that TikTok content being uploaded onto its platform was a frequent issue. It said all content featuring minors constitutes a violation of user guidelines, and that the content Rolling Stone found would be removed for further review. “Pornhub has a steadfast commitment to eradicating any and all illegal content, including under-age material, and actively works to employ state of the art, comprehensive measures to protect its platform from such content,” including technology that “aids in finding and removing known images of child exploitation,” a spokesperson said.

Pornhub aside, it is not uncommon for underage TikTokers’ images to appear on other platforms like Reddit without their consent. “This happens all the time, sadly,” @bloodbathbey0nd tells Rolling Stone, pointing out that underage TikTokers don’t often reveal their real ages on the platform, further complicating matters. (Ironically, her own video was later pulled from TikTok, presumably because she uses the word “porn” in it.)

She points out that adults on TikTok have also been uncomfortable about minors doing the WAP dance, a risqué dance set to “WAP” by Cardi B feat. Megan thee Stallion; many TikTokers have rallied for influencer Charli D’Amelio to perform the dance, despite the fact that D’Amelio is only 16. (There are numerous WAP dance TikTok videos posted on Pornhub.) “When kids get the instant gratification of gaining tons of followers from doing these trends, it only feeds their desire to do more videos similar to it,” @bloodbathbey0nd says.

In a statement to Rolling Stone, a spokesperson for TikTok said that the platform would be removing content associated with the audio for the arch trend that violates its policies regarding minors. “Content that sexually exploits, targets, or endangers our users is abhorrent in any form and on any medium, and is strictly prohibited on TikTok. We are keenly protective of vulnerable populations, including minors, and we will continue to monitor potentially problematic activity and remove any content that violates our Community Guidelines,” the spokesperson said. Many of the videos associated with the trend since appear to have been removed.

TikTok’s user guidelines prohibit “content that depicts sexual exploitation of minors,” as well as “content that depicts sexual activities such as penetration, non-penetrative sex, or oral sex involving minors.” A BBC News investigation last year found hundreds of sexually explicit comments on the pages of TikTokers as young as nine years old.

Over the past year, TikTok has exploded in popularity, reporting 100 million monthly users in the United States as of last August, up 800% since January 2018. Its user base skews young, with approximately 41% of its users between the ages of 16 and 24, according to Omnicore Agency data. The app made headlines last week when President Trump announced his administration planned to ban the Chinese-owned app from U.S. app stores for national security reasons, only for him to approve a deal between the app and the tech company Oracle.

Given the explosive growth of TikTok, some creators are skeptical that it’s sufficiently policing content from underage users. “TikTok, much like early 2010s YouTube, has a massive problem with how popular they are, and how much content gets uploaded at any given moment,” says @bloodbathbey0nd. “[I] honestly don’t know what TikTok can do to prevent this, other than increased moderation.”