I have noticed that at a few caches I have visited it lists many TB's in the inventory. When I get to the cache there are no TB's and no mention of anyone taking any TB's in the log book or online.
A few big ones recently were
GCJHNB Jetport Travel Bug Hotel 5 Trackables Missing
GC17M27 Bears In The Bushes 4 Trackables Missing
GCxH5M B.F.I 8 Trackables Missing
There are always a few missing here and there but this is a bit rediculous. This seems to be more than your average cacher forgetting to log a trackable here and there.