Originally Posted by Camper_bob
Yeah, that would be a problem. I use it more for security under way to ensure the coupler doesn't somehow come unlatched. It's true; a lock up there is easy to defeat for even marginally motivated thieves, especially if they have time and privacy, like in an unmonitored storage facility.
For "underway security", we found the best coupler/receiver lock pin
at Lowes, and not where you'd expect it ... but in the nut/bolt bin area of the hardware section.