TheMadScientist - 6:41 am on Feb 3, 2013 (gmt 0)
This sorta says to me that unless you block all blank referrers, which could have some unintended consequences, there isn't any way to intercept those requests.
You can separate Google IP addresses from 'everything' so you don't have to block all blanks ... But, the technicalities of 'getting things right' are really more for the Apache Forum, in my opinion, so I'll just leave it at:
You don't need to block all blanks; mod_rewrite is way more powerful and useful than an 'all or nothing' type statement.