Here you go, April 2016 rewrites for your .htaccess file. Just place it in and you will get less referral spam.
I go to each spam site and see there are a variety of sites this month. Many of these seem to be legitimate websites who probably hired Ukrainian SEO companies practicing black hat SEO. I get the listings from a variety of sites that range from Cannabis growing to the latest tech toys.
As there are less and less porn and strange hormone sites and more and more sites that are actually doing something normal I am seeing a trend that shows more websites are desperate for traffic hits and desperation leads to horrible results.
Once your site reaches our list of referral spammers you are branded as an outcast, not a good thing. So check with our list each month and see who has been added.
I guess I will soon go back to see which sites have dropped their black hat SEO and stopped their spamming so I can cull the list back to save on load time. But until then these monthly updates will keep your site relatively safe from referral spam and you can finally see, in your log files, just who is driving traffic to you. Legitimate traffic.