YouTube has announced that publishers will now be able to have comments with links or hashtags to be held for review.
“We’ve heard from many of you that comments with links on your videos are often low quality, and you’d like a better way to moderate these. Today, we’re making it easier for you to block comments that contain links and hashtags with a new setting in Creator Studio. If you enable this setting, comments on your videos that contain links will be sent to your Held for Review queue before being published.”
The article includes more details and analysis.