Use .htaccess to ban them from even opening up your site in a browser.
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If you want to deny access to a particular individual, and you know the IP address or domain name that the individual uses to connect to the Internet, you can use .htaccess to block that individual from your web site.
<Limit GET>
order deny,allow
deny from 123.456.789.000
deny from 456.78.90.
deny from .aol.com
allow from all
</Limit>
In the example above, a user from the exact IP number 123.456.789.000 would be blocked; all users within a range of IP numbers from 456.78.90.000 to 456.78.90.999 would be blocked; and all users connecting from America Online (aol.com) would be blocked. When they attempted to browse your web site, they would be presented with the 403 Forbidden ("You do not have permission to access this site") error.
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That was taken from
http://www.hostingmanual.net/other/htfun.shtml Obviously the author doesn't know much about IP ranges.
But the idea still works.
