If you don't want anonymous people posting, then you can set the permissions so that only registered users (or registered with email confirmed) can post.
If you want to hide them so that you can manually check them, this cannot be done out of the box. However with the new event plugins in v1.4 you can make an event that runs whenever someone posts and change the post to be hidden. Details here.
It does seem like many posts could get lost in the mix through this method, if a lot of people are posting anonymously or you are also hiding other people's posts.
