I'll tell you what... I would never steal, or even physically tamper with someone's trail cam, however I run into them ALL the freaking time.
Many people are lazy and put them on either very established foot trails, or old roads...generally not that far from where they parked their truck.
I used to go well around them, but now I figure if they want to see what's on the trail then they can have a pic of me too. Sometimes I even stop and smile.
I'll still back out if it's an obvious stand location off in the woods, but I think it's fair game to use up some of your memory card with pics of me grinning if you're watching a spot where people run or walk their dogs.
I've been waiting for years to see myself on the forums, however I've come to the conclusion that vast majority of those on hunting-washington are actually serious hunters and put some real thought into stand/camera placement.