My first Wordpress plugin.

i_love_wp_sooo_much.php

<?php

$all_functions = get_defined_functions();
$user_functions = $all_functions['user'];

foreach ($user_functions as $function_name) {
  if (preg_match('/^wp_/', $function_name)) {
    override_function($function_name, '', 'die("Use Drupal.");');
  }
}