This module will allow you to give your users warnings.

1. Run the following composer command:

   php composer.phar require eye4web/eye4web-zfc-user-warnings

2. Enable it in your application.config.php file.

   <?php
   return array(
       'modules' => array(
           // ...
           'Eye4web\ZfcUser\Warnings'
       ),
       // ...
   );

If you want to ban the user after X warnings you can make user of Eye4webZfcUserWarningsBan.