Some people have mentioned that they were a little concerned that RSPeer knew their account data to log back in, without having an account manager; so I will put an explanation down here to put those feelings to rest.
Whenever you log in to Runescape, the game stores your account data in two static fields called: username and password. These fields are set in every client by Runescape simply because that’s how the game operates. The only extra step RSPeer takes is remembering these two fields, set by the game, after a script is started. This information is not stored to the disk, it is simply inside the active memory while the client is opened, just like Runescape stores it while you’re logged in. When you are logged out due to a disconnection, the 6-hour limit or any other reason, RSPeer simply uses this data to log you back into the game. As soon as you close the client, the data is forgotten. No sketchy business, just convenience.