Google-owned YouTube is rolling out a change to its platform that will see comments disabled on most videos featuring young and older minors.

The company on 28 February said it will begin blocking users from commenting on most videos that feature kids younger than 13. It will also disable comments on videos including children between 13 and 18, if the content invites predatory behavior. It's enacting this new policy in response to reports that pedophiles were using a comment loophole of sorts to track and exploit children in videos.

YouTube said its new policy, which will rely on software algorithms to identify minors, is expected to take several months to go into effect:

"Over the past week, we disabled comments from tens of millions of videos that could be subject to predatory behavior. These efforts are focused on videos featuring young minors and we will continue to identify videos at risk over the next few months. Over the next few months, we will be broadening this action to suspend comments on videos featuring young minors and videos featuring older minors that could be at risk of attracting predatory behavior."

This move comes shortly after YouTube creator Matt Watson (MattsWhatItIs) posted a video to show how YouTube’s algorithms allowed pedophiles to post sexual comments or timestamps on kids' videos to identify parts where they're seen in compromising positions. The videos themselves are not pornographic, but pedophiles were using a loophole to sexually exploit kids or trade child porn.

Watson's video went viral and generated a huge discussion on Reddit, prompting companies like Disney and Nestle to suspend their ad spending on the site. YouTube responded by removing millions of comments and about 400 channels involving minors. Now, YouTube is announcing a policy change as well as new software that will be able to effectively find and remove predatory comments.

This new software, or classifier, will not affect the monetisation of a video.

YouTube also confirmed a small number of young creators will be able to keep comments enabled videos. But those channels will be required to "actively moderate their comments, beyond just using our moderation tools, and demonstrate a low risk of predatory behavior".

The company promises to work with those channel directly and to improve its ability to catch "violative comments".