> the client might not be running as your user on your local machine True, this ...

		rnhmjoj 17 hours ago \| parent \| context \| favorite \| on: The X11 Security extension from the 1990s > the client might not be running as your user on your local machine True, this is probably the only real use case. X11 forwarding in OpenSSH (ssh -X) does in fact use this extension by default.