ban_user.php

<?php
 
// change these to match your app
$app_id = '1234567890';
$app_secret = 'abcdefghijklmnopqrstuvwxyz';
 
// init facebook class
$facebook = new Facebook( array( 'appId' => $app_id, 'secret' => $app_secret ) );

/* Ban Users */

// call POST {app_id}/banned/ using app access_token and comma separated list of uids
$ban = $facebook->api( $app_id . '/banned', 'POST', array(
    'access_token' => $app_id . '|' . $app_secret,
    'uid' => '1234567890,5678901234'
  ) );

// $ban will return true if successful
print_r( $ban );

/* Unban Users */
 
// call DELETE {app_id}/banned/{user_id} using app access_token
$unban = $facebook->api( $app_id . '/banned/' . $user_id, 'DELETE', array( 'access_token' => $app_id . '|' . $app_secret ) );

// $unban will return true if successful
print_r( $unban );