Things have gotten so bad with the #BirdBox Challenge that YouTube has updated its policies to explicitly prohibit pranks that could cause harm to people.

“Content that encourages violence or dangerous activities that may result in serious physical harm, distress or death violates our harmful and dangerous policy, so we’re clarifying what this means for dangerous challenges and pranks,” a YouTube employee said in a blog post. “YouTube is home to many beloved viral challenges and pranks, but we need to make sure what’s funny doesn’t cross the line into also being harmful or dangerous.”

In December, the #BirdBox Challenge went viral after the Netflix original of the same name was viewed by thousands of people. People have posted videos doing a range of activities while blindfolded including reenacting scenes from the movie and driving — which has obvious safety concerns.

Netflix even stepped in to stop people from participating in the challenge.

Previous viral challenges have also caused issues for brands and challenge participants. YouTube’s newest policies aim to stop users from harming themselves through pranks and other challenges. Last year’s Tide Pod Challenge went viral after YouTubers filmed themselves eating the product, getting many people sick.

YouTube is giving users a grace period on content that violates its Community Guidelines—users will not receive a strike for their content, but it will be removed.