Geocachers,
 
I checked the profile for rhodopogon, and I see that this user is not a Premium Member. Geocachers can make it more difficult for "rogue" geocachers like rhodopogon to view caches by making them "subscriber-only" caches.  Therefore, rhodopogon would have to pay $30 per year to get a Premium Membership to view this cache.  $30 per year (less than the cost of a tank of gas or less than one-tenth the cost of the most popular GPS units) is minimal for serious geocachers but will likely deter most rogue geocachers like rhodopogon who post harrassing notes or who may steal or plunder caches.
 
Even if such individuals did pay the cost to become a Premium Member, an owner of a "subscriber-only" cache could use Read the audit log feature to see who has viewed the cache.  

Ken (a.k.a. Highpointer)