Campground thefts are far more common than in the boonies -- thieves go toward the low hanging fruit, not to where the pickings are slim!
And even then, it depends on where the campground is. We were in rural Oregon once, and we were locking our generator to the trailer tongue. Someone walked by and said, "I can't see your license plate, but I will bet you are from California!" (Where I live, anything not locked will take a walk.)
Once in a while, if we are boondocking near a city, we will lock the hitch with one of those gorilla attachments.
Bottom line -- after hundreds of days of boondocking, we have never lost anything.