I've started adding a 2nd set of rules to my htaccess file becasue some sites are getting past the normal htaccess
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^
http://.*YOUR-DOMAIN-HERE/* [NC]
RewriteRule .*[jJ][pP][gG]$|.*[gG][iI][fF]$|.*[pP][nN][gG]$
http://die-like-a-stuck-pig.com
RewriteCond %{HTTP_REFERER} ^
http://.*count-password.com/* [NC]
RewriteRule .*[jJ][pP][gG]$|.*[gG][iI][fF]$|.*[pP][nN][gG]$
http://die-like-a-stuck-pig.com
You may notice the 2nd RewriteCond does not have the ! which means not equal if that helps it make sense. This is how I block the smater sites and it's been working well for me so far.