YouTube is trying to prevent otherwise bright people from doing dangerous things.

The video-sharing network owned by Google is cracking down on harmful or dangerous pranks and challenges.

Updated policies no longer allow challenges that present "an apparent risk of death" and ban content featuring children "participating in dangerous challenges that pose an imminent risk of injury or bodily harm."

A recent "Bird Box challenge" featured videos of people engaging in activities while blindfolded. At least one car wreck was attributed to a person attempting the challenge while driving. People also were sickened in a challenge that involved eating Tide detergent pods.

"Any one of these things or combinations of events can really become tragic,” says Dr. John Paul Tutela. “Whether it's a fatality or permanent injury and permanent disability.”

YouTube also says it is drawing the line on content that "intends to incite violence or encourage dangerous or illegal activities" that have a risk of serious harm or death. They include bomb making or pranks that put people in physical danger.