title: Allow only registered users to comment on WordPress blog posts
body: <p>The question is quite simple : How can I restrict unregistered users to post on my WordPress blog?
  I was thinking about a plugin that would hide the "comments" part if user is not logged in, but 1) I don't know if it is possible, and 2) there is certainly a easier way to do this.</p>
  
  <p>Thanks!</p>