Spy on Internet Users with: 1-Pixel GIF File, in Base64

This little bit of code returns a 1-pixel gif file. You can add it to the bottom of any script that you want to call from an IMG tag.


<?php
header('Content-type: image/gif');
echo base64_decode('R0lGODlhAQABAIAAAP///////yH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==');
?>