A Frames when you leave to go shopping etc....

No trailer is secure enough to prevent a large screwdriver or prybar opening every door and compartment.

An Aliner is as secure as any travel trailer which isn't saying much.

In campgrounds I often leave it unlocked. I do lock at retail areas, truck stops, rest areas, etc. I have no illusions though that those locks will stop someone that is willing to do damage and has a few minutes unobserved.

I just don't worry about it, that is what I have insurance for.