How to block FireSheep without using SSL

So the firefox extension FireSheep lets you side hack non ssl website.
This should be easy to block without having to use SSL.
Just save the IP address when you first assign the session id and then check it every time the session id is used.
It's easy. Just a few lines of code (only 2 really)

Here is the code: (change the message to whatever you want) place it as first line after session_start() if ( ! isset($_['cookieIP']) ) {$_['cookieIP']=$_SERVER["REMOTE_ADDR"];} if ($_SERVER["REMOTE_ADDR"] != $_['cookieIP']) { echo '<html><body><center><font size=5>You Are A Hacker!<br><br>The FCC has been notified of your IP '.$_SERVER["REMOTE_ADDR"].'</body></html>'; exit; }

Website design - Smarter Business Websites - Database Website design - Expert Database Website Design -