I'd focus more on protecting the items of value on your campsite. I may be naive, but I've never given theft of the trailer much thought. When on a campsite there is about zero possibility of someone going thru the effort to steal your trailer. The only things I worry about are easy to grab items like our bikes and generator. I keep the generator locked in the back of our truck so it's out of site and we lock the bikes to a tree or to the popup itself when off the site. I keep our bbq and stove out during the day and haven't had anyone walk away with that and find most campers do the same. I do keep a padlock on the coupler while the trailer is in our laneway at home, but that's the extent of my security. Every day on my drive to work I pass through mennonite country and they have stands set up on the road side everywhere with just a bowl to put your money in and take your change for the items they have to sell. No one there to watch and when I've stopped to get the wifey flowers there's been easily $100 sitting there in the bowl. If people stole often they wouldn't sell that way. The majority of people are honest. Knock on wood, I've never had anything stollen from me yet.