Beeslave: thanks for clearing that up. I have talked to people that do move them just to annoy the cache owner.
The GPS does not get to the exact location. Many times it is 5-25ft off from the location it actually is. This is do to many factors, but most caches can be found in less than 20 minutes looking for it.
Some are very easy to find, others are not. For instance, the large red coffee can sitting on a stump behind some bushes is easy to find. A hollowed out bolt with a nut and magnet placed on a bridge or other structure with visible nuts and bolts is a much harder thing to find. Also, some of these caches are smaller than the eraser on the end of a #2 pencil.
Yup, road kill with surely make the 3 year old that opens the box happy.