Having had this problem many times [:@], the best course of action is the civil one. I usually try to catch the guy coming or going (Fri. Night, Sat. Morn, Sat. Night are usually when you can guarentee that they will hunt.) At that point, if the guy is civil, I tell him I'd like the stand moved from my property right away -- 2 days or so. If he's a jerk and it's a easy to remove stand, I'd remove it and tell them not to come back. If it's nailed or bolted to the tree, I'd leave it and use it and tell him if I catch him there, I'll remove the bottom two steps while he's up there adn return with the Cops. It usually works...