Semi Private posts

Hello,
Is there a way for the originator of a post or blog to somehow control who adds replies or comments to it? If not, perhaps there should be something more than just Flag as offensive. It seems like someone, while still following Vs rules, can easily sabotage, threadjack, bad mouth the originator, or just make so much noise that other users either lose interest or avoid replying to the post, causing the topic to die. A solution: When someone starts a new post or blog they could click on a Public or Semi Private box. When the originator chooses Semi Private, all guests and users can still view the post, but anyone wanting to add to the post must first type out their reply or comment, and then request of the originator that their reply be added. It wouldn't be censorship because if the originator of the post declines to have someone's reply added to their post, they can just start a new post of their own.