You can stop those with a simple line in htaccess...
One of the other GFY webmasters posted this link a little while ago. ( cheers to the poster )
http://www.sponsorpost.com/resources...ard/index.html
Thats for free .. may need to be changed for different OS's but Im sure your host can handle it. Im sure one or two of those type programs will spoof a URL but if its stops most of them thats good enough.