Funny, I own a campervan and have driven all up and down the west coast. The one single time I had something weird happen, it was in the middle of nowhere in a forest in Oregon. Parked on the side of the dirt road in a little side road off the main road. Was sound asleep when I heard a banging on the door. Must have been 3am or something... I got up and peered out the window covers and saw a guy standing there yelling at me to open the door. It was freezing cold out and he was wearing not much clothes for how cold it was. He looked like he had been sleeping in the forest for quite some time (dirty, long hair, beard). I yelled back at him no way that I was going to open the door and he yelled something back at me and stormed off. Didn't hear anything from him again. Grabbed a knife to keep it close and went back to bed. That was one freaky weird experience. I thought about driving off, but didn't want to try to find another place to park in the middle of the night and it seemed like he was gone so I just let it go.
That is indeed weird but could even more easily happen in downtown Portland as in the middle of the woods. I definitely think you need to maintain situational awareness and carry protection, but that is true of any kind of travel.
I also spent 2 years living on a motorbike went 15k km all over Vietnam, Cambodia and Laos... some of the most remote places... never once had an issue with anyone.
That said, in this case, I wasn't sleep out in the middle of a forest but I do have friends who do it more camping style and they haven't had issues.
I guess it is all just luck of the draw (or some say, karma).
