We discussed this last year too. If you leave a stand on public land, I argue that you are, in effect, claiming that spot. Even if you are the easy going sort of guy that would see another hunter in your stand (that you left on public land) and just walk somewhere else.
I scout the heck out of the public land I hunt and know it very well. There are a number of really good spots that I'd like to be able to use (assuming I'm the first there that morning, of course) depending on wind and so forth. However, throughout the year, someone will go in there and hang a stand. When I or anyone shows up in the morning - even though the stand owner isn't there, now we have to decide do we want to risk that guy coming in and blowing our hunt? Do we want to risk a confrontation (even assuming I don't - and I wouldn't - sit in his stand)?
Probably not - it just seems incredibly rude to me to leave your crap out there on public land and expect everyone else to respect "your" spot. And Brian - if you leave your bow out on public land for weeks at a time - I wouldn't be all that surprised if someone found it and walked away with it.
How about this - exactly what is required to claim a spot? As mentioned I have a number I like to use. Do I need to festoon the woods with cheap stands to keep other taxpayers out of my private public spots? What about lawn chairs - would those do? How about if I just leave soda cans out there - is that still my private property and good enough to claim a spot or is it just abandoned trash ? That's what I argue those stands that hang out there for weeks at a time must be.