It's quite simple, a hacker picks his/her target because he/she feels like it.
Code:
<?php
for ($a = 1; $a <= 4; $a++) {
srand((double)microtime()*1000000);					
$randvalue = (int)rand(0,255);
if ($a == 1) { 
$a = $randvalue;
Else {
$a = $a . "." . $randvalue;
}
}
?>
No idea if that'll work, but I'm bored :P
- Noia