Cute dogs, but we seem to have drifted off topic a bit...
I have a king pin lock that I use for storage but never at the campground (even beach days where we're going for 8+ hours). I figure if the crook is going to break in AND move all of our stuff to put in the 4-slides, (s)he's determined!
I do like up our bikes - only mine was expensive, but the two ladies might get miffed if I leave theirs unlocked while locking mine up. But it's more for looks as it is a cheap cable.
And- depending on where and who I'm camping with, my truck keys are possibly laying on the floor or center console! Yes, even overnight as in my tent camping days, I've had to use the 12v cigarette lighter outlet for my CPAP machine.
We tuck things under the awning or camper at night, but that's more for dryness than security.