static function insertFacebookUser($validUser)
 {
     $userId = DBConn::insert("INSERT INTO " . DBConn::prefix() . "users(name_first, name_last, email, facebook_id) " . "VALUES (:name_first, :name_last, :email, :facebook_id);", $validUser);
     if ($userId) {
         GroupData::addDefaultGroupToUser($userId);
     }
     return $userId;
 }