I would have to disagree frost. If you are just wandering around and a person join and they happen to find a rare it should be theirs unless you called it before hand. It's not like that person is stealing all his rares, they are just luckier. That is how i see it.
Now of course you kill the monster and they go and swipe it or start camping that is something different but instead of getting gm i would say make a new game and have a password.
I'd let them know if i'm specifically hunting something. but I'm talking about just leveling and everyone else getting luckier than I do. I play on my own and nothin. Someone joins and they immediately get stuff. It's just infuriating lol I don't blame them, that's just how it goes.