LOS ANGELES (CBSLA) – New concerns are being raised over inappropriate content children are being exposed to online, even on sites specifically targeting kids.

Despite its name, YouTube Kids – as 7-year-old Tanner Markham found out – isn’t always so kid-friendly.

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A figure with large, protruding eyes and a distorted mouth appears with a voice chanting, “Momo, momo. Momo’s going to kill you.”

“It was creepy, it had a V-shaped mouth,” Markham said.

Pediatrician and mom Dr. Free Hess was disturbed by what she found: Violent content, sexual innuendos and clips spliced into kids videos that include a man giving tips on suicide.

“We have no idea what seeing this content does to children, their brains are are not fully developed so they’re not able to think through complex situations such as the things that they are seeing,” Dr. Hess said.

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Diana Graber of Capistrano Beach wrote the book “Raising Humans in the Digital World.” She says when it comes to YouTube, the best defense is to watch with your kids.

“I think this is a really good reminder for parents that we cannot leave kids with devices or YouTube or with anything online,” Graber said.

Google, which owns YouTube, told CBS News in a statement, “We rely on both user flagging and smart detection technology to flag this content for our reviewers. Every quarter we remove millions of videos and channels that violate our policies.”

But in Studio City, parents like Alexis Coulter say when it comes to YouTube with their young kids, they just say no.

“I’m very aware having to protect that space,” she said. “It’s really hard now being a parent because parents don’t have the control that you had when I as a kid.”

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Experts say the problem isn’t unique to YouTube Kids, but the app is getting so much attention because of its popularity with children.