You can report to moderator by clicking on the options menu located at the top right corner of the post. But either the post can be deleted or modified based on the request and it will not be made private. What is the reason you want to make it private, since its a public forum?
If you are talking about this then i find it to be pretty generic. And as mathan as suggested this is a public forum and the message can either be moved to any thread or deleted completely...