[Az-Geocaching] Who took my geocache San Juan Overlook?

Several months ago, I received a note from an experienced geocacher explaining that he couldn't find my cache San Juan Overlook in South Mountain Park. Today I checked the cache, and unfortunately it is gone.

I don't understand why this cache is missing, because it cannot be seen from the trail and I thought that it was well-hidden. It did appear to me to be better hidden than many other caches in South Mountain Park that are still in existence, some of which were established before San Juan Overlook.

What could have caused this cache to disappear? Someone who knew of the existence of the cache (a rogue "geocacher", perhaps) must have taken it.

Two of my other caches, Phoenix Open (gone for the second time, even with a smaller container) and Estrella FREE Car Cache (difficult to get to and quite remote, so there is no way that it could have been found accidentally) also appear to be missing. This may sound a bit paranoid, but could there be someone out there who doesn't like me who is taking my caches?

Ken (a.k.a. Highpointer)