Unfortunately, the in-game means really do generally boil down to "don't trust newbies."
That's how we end up with the destructively secretive culture that developed in the EC and AT years ago, where no one joining the realm was allowed access to any significant information for weeks or months after joining.
The best way to discourage this, in my view, is for the culture of the game to be such that anyone who tries it will be told, "Not cool, man," and the realm he's doing it for refuses to take his info and bans him.