I would like YouTube to consider adding a "Subscriber Only" option for the comment section of YouTube videos, whereby only viewers subscribed to the video owners channel would be able to comment.

In addition, there would be a minimum waiting period of 1-2 days after subscribing before the option would become available. This would deter users from simply subscribing, posting a comment, then immediately unsubscribing.

While this, by no means, would eliminate all hateful or useless comments, I believe it would greatly reduce the amount of abuse that currently plagues the online community and its creators.