I know. My point was that Chrome does not have a security advantage over Firefox on X11, since the discussion was about the security advantages of Chrome/Chromi

I know. My point was that Chrome does not have a security advantage over Firefox on X11, since the discussion was about the security advantages of Chrome/Chromium over Firefox. We are in full agreement. On X11, the security model is: every application can see/do everything. You should only run an application in X11 when you fully trust it.