We have never had anything taken.
But in talking (OK shooting the bull) with a park ranger (State Park type) and asked that same question. He said the stats he looks at, crime is up and mostly in "day use areas" and the same old thing. Ice chests missing from back of pick ups when people are out playing (swimming etc). From the actual campground itself most complaints are generated from dogs, kids and drinking. And their major fights are drinking inspired at family get togethers. (To funny, family re-union and two brothers in 30's, one stabbs another with BBQ fork, sort of ends that re-union)