RE: Tree stands
Sher have... Lots of people around here hang 'em up on the gamelands, and if I've got no reservations about hopping up in one that I come across to eat my lunch or just check out the view. I don't get mad if somebody else uses mine, so long as it's there when I get back!
You're not supposed to build wooden stands on PA gamelands, but guys do it anyway.
For deer hunting, however, I'm very particular about stand location, so I always use my own. While turkey, coyote and small game hunting, I move around calling and scouting and that's usually when I wind up snooping around random treestands. Nobody else is out on those days anyway.
I don't trespass, so don't jump to that conclusion, and I surely don't care if somebody else uses my stand if I'm not there. They'll probably be careless with their scent, move around too much and get skunked anyway.