I have two good hunting buddies and just so happens I showed both of them where to place their stands... then I made it prefectly clear to them that I don't want to see them hunting near my stand. I also explained the traffic pattern to them and the primary runs... if yu don't know what you are doing one guy can cut off the other two.This is an area I have hunted since 1974... it's 2 miles from where I park the truck. Nobody wanted to walk into this area before...now atv's have made it easy. So my situation is very similar to yours. Part of hunting is just that... HUNTING. And you can't hunt with people all around you.
Both of these guys are great and we hunt well together... mainly because we set parameters we all expect each other to abide by. Don't get me wrong... I'll let either one of them hunt out of my stand and be happy for them if they score... but I don't want them encroaching on me.

By the way... I agree with the other posters who said if he is your friend approach him in a nice way. Tell him... hey Frank(or whatever his name is).. I knowyou are unfamiliar with the runs round here and the traffic pattern but you placed your stand right on my primary run... I'd like you to move it toanother run I'll show you that's just as good... then we both have a chance to score... if he says NO... then write him off as a friend... but I doubt he will. Up here in NY there are places where you can actually hunt within eyesight of others and not be cutting each other off... maybe that's what he's use to??