<?php if(JFactory::getUser()->guest) {
//do user logged out stuff
?>
<li><?php echo $this->item->extraFields->alias1->value ;?></li>}
else { 
//do user logged in stuff
<li><?php echo $this->item->extraFields->alias1->value ;?></li>
<li><?php echo $this->item->extraFields->alias2->value ;?></li>
<li><?php echo $this->item->extraFields->alias3->value ;?></li>
<?php } ?>