I was under the impression that Jagex viewed gold and items as intellectual property and that we as players just have access to them. As far as I've known, rwting is an illegal crime, but I highly doubt Jagex is going to go out of their way to take any legal action unless there was some extreme case. However semi-related, I do remember reading a story about someone robbing another individual at gunpoint for their gp after meeting them for an irl exchange. I believe that the person that stole the gp was arrested, but that is probably a little bit more different than the situation that you are asking.