      </div>`
 
 ItemScreen = React.createClass
-  mixins: [HasScreen, HasComments, DOMEvents, FocusController]
+  mixins: [UserAware, HasScreen, HasComments, DOMEvents, FocusController]
   propTypes:
     model: React.PropTypes.instanceOf(Item).isRequired
   focusItems: '.ItemView'
 
   renderAddCommentButton: ->
-    unless this.state?.commentEditorShown
+    if not this.state?.commentEditorShown and this.getUser()
       `<div class="Controls">
         <Control onClick={this.onAddComment} icon="comment" label="Discuss" />
        </div>`

     </div>`

CommentView = React.createClass
  mixins: [HasComments, HasScreen]

  propTypes:
    model: React.PropTypes.instanceOf(Item).isRequired

      <div class="meta">
        <ItemView full item={this.props.model} />
        <div class="Controls">
          {this.getUser() && <Control onClick={this.onAddComment} icon="reply" />}
          <Control href={this.url()} icon="link" />
        </div>
      </div>
