One of my TB's recently went missing in Kinver Edge NT. As far as I can gather the NT use their own unpublished caches for some training/educational purpose.
Last logs....

2/Oct/2012 teamwalters grabbed it
Moved it to a cache nearby owned by Kinver Edge National Trust. Sorry
don't know cache name as I don't think it's been logged.

28/Sep/2012 teamwalters
discovered it Found it in Kinver Rock and Roll (GC3HYTV) cache.
Moved it to National Trust cache nearby.

I wrote to Kinver Edge NT and received this reply today,
according to Laura Broadhurst, NT Kinver Edge,

"Sorry I just wanted to let you know that I didn't find the travel bug, not
all of our caches were still in place though - they quite often get stolen
up there."

Is there any way we can stop this pilfering/looting of genuine geocaches for use in private unpublished pseudo caches?