I would be pissed off too, but it's really not your place to confront the guy seeing that it is not your land. It's the landowners resposibility. You need to talk to the owner and see what he wants to do. He can have him prosecuted, or executed, if he wants.Of course he may try to get revenge if he is arrested. I would talk it over with the landowner first. He may want you to take care of the situation. Be careful though, some people think it's there right to be anywhere they please. Just dig a deep pit and put spikes in the bottom and..., well you better not do that.