code: public function logoutAction() 
      {
          $this->zfcUserAuthentication()->getAuthAdapter()->resetAdapters();
          $this->zfcUserAuthentication()->getAuthAdapter()->logoutAdapters();
          $this->zfcUserAuthentication()->getAuthService()->clearIdentity();
  
          $data = array('logout' => (int) !$this->zfcUserAuthentication()->hasIdentity());
          return  new JsonModel($data);
      }
docs: (non-PHPdoc)
  @see \ZfcUser\Controller\UserController::logoutAction()