Index: wp-includes/user.php
===================================================================
--- wp-includes/user.php	(revision 27354)
+++ wp-includes/user.php	(working copy)
@@ -620,7 +620,7 @@
 				elseif ( preg_match('|^https?://|', $search) && ! ( is_multisite() && wp_is_large_network( 'users' ) ) )
 					$search_columns = array('user_url');
 				else
-					$search_columns = array('user_login', 'user_nicename');
+					$search_columns = array('user_login', 'user_url', 'user_email', 'user_nicename', 'display_name');
 			}
 
 			/**