A word about theft? I was concerned about theft also as my surge protector is the plug-in at the pedestal type. Considering I always carry extra 30 amp RV cord (2 - 50 foot lengths), I plug one of these cords into the pedestal, run it under the camper and then plug in the protector. I then take the trailer cord and plug it into the other end of the protector. The actual protector then fits very nice on the top of my tires on the door side of the camper. Because it's kind of wedged between the top of the tires and the top of the wheel well, you rally cannot even see it unless you get right upon the wheels, which is also under the awning, beside the door and under the outside kitchen.
Any kind of locking device will never stop a thief. But if a thief does not even know it's there, they'll move on. "Out of sight, out of mind!" This works very well for us.
Edit:
Here's a photo from our Florida trip we made over Christmas 2013. I bet you have to look real hard to find the surge protector. Look on the top of the front wheel.
Here's the protector at home (we live in the country ... if someone takes it from our home, well, they need it MUCH more than I do then).