Kinda funny, but I had not thought about this before. I was looking over the Alabama regulations, and found the following:
3. Shoot or hunt a turkey from a treestand with a firearm. All other legal game animals and birds may be taken with a bow and arrow or firearm from a treestand.
I don't know if it's illegal everywhere, and I don't know if anyone actually does it, but I thought it was an interesting regulation. I wonder what the benefit would be to try that, and why you wouldn't be able to. Maybe they don't want you to set up a tree stand near a roosting tree? Huh.