I've used rsbot powerbot arbibots and nexus nothing has stolen my 9 active accounts yet. Did someone just make up this stealing account crap because people left their accounts unsecured to friends and clan mates?
All I can say is now that free trade is back, everyone has a motive to hack people's accounts. It's simple, gp=$$$. Before free trade it was such a hassle xfering/having a method that it really wasn't worth all the work.
He asked because of the giant powerbot hacking incident. Apparently Arbiter had nothing to do with it. He possibly may have known and this is why he left and made his own client.
It is safe so far, I would advise waiting a week or two though before you use it.