So what’s the solution?
Get off the web quick!
Nah, I’m just kidding. There are a number of things you can do to reduce the effect those spam bastards can have on your site though I don’t think you can completely get rid of them.
You can start by not displaying your referral logs. If you’re using something like Refer 2.0, password protect your refer folder. You can do this easily through Cpanel.
Now, if you’re comfortable with tooling around your .htaccess here’s a tutorial to help you block spam referrers through .htaccess.