Index: wp-includes/post-template.php
===================================================================
--- wp-includes/post-template.php	(revision 20832)
+++ wp-includes/post-template.php	(working copy)
@@ -560,6 +560,9 @@
 	if ( empty( $post->post_password ) )
 		return false;
 
+	if ( ! apply_filters( 'post_password_required', true ) )
+		return false;
+
 	if ( ! isset( $_COOKIE['wp-postpass_' . COOKIEHASH] ) )
 		return true;