I have never actually worried about it much at all, especially in campgrounds where you are surrounded by like minded fun seekers. If needed when boondocking, I do mostly use it when someone is still around the area of the trailer.
I did have a portable panel stolen last year, but that is when someone broke into my trailer being stored and stole all the easy to take and use stuff. I hope they were confused by my rewiring the solar to 36V and have an MPPT controller to handle it.