Facebook API没有得到响应的非注册应用程序用户

当我通过创建它的用户登录时，它会返回帖子，但对于其他用户。

$facebook = new Facebook(array(
    'appId'  => 'xxx',
    'secret' => 'xxx', 
    'cookie' => true
));
$user = $facebook->getUser();
$par = array();
$par['scope'] = "status_update user_about_me user_status,user_post,user_stream";
if ($user) {
    $logoutUrl = $facebook->getLogoutUrl();
    try {
        // Proceed knowing you have a user who is logged in and authenticated
        // Get Feed
        $feed = $facebook->api('/me/feed');
        // Get User Profile
        $profile = $facebook->api('/me');
    } catch (FacebookApiException $e) {
        error_log($e);
        $user = null;
    }   
}